{"title":"ECU \u0026 Harness Kits","description":null,"products":[{"product_id":"holley-efi-can-input-output-module-kit","title":"Holley EFI CAN Input\/Output Module Kit","description":"\u003cp\u003eAdds Up To (8) Inputs and Outputs\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"Holley EFI","offers":[{"title":"Default Title","offer_id":49432984355054,"sku":"HLY-554-165","price":519.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0819\/9110\/6798\/files\/Screenshot2026-08-17211429.png?v=1787019277"},{"product_id":"hp-efi-ecu-harness-kits-550-602","title":"HP EFI ECU \u0026 Harness Kits 550-602","description":"\u003cp\u003eGM LS1\/LS6 (24x crank sensor) with Jetronic\/Minitimer (Bosch type) connectors on injector harness, Includes Bosch Oxygen Sensor\u003c\/p\u003e\n\u003cp\u003eFeatures:\u003cbr\u003eIdeal For Everything - including stock 5.3L engine swaps or all out, 3,000+ horsepower race cars that need a simple and powerful ECU and harness solution\u003cbr\u003eOptional plug and play hand-held programmer, 5.7\" touchscreen and digital gauges are available for ultimate control and vehicle monitoring\u003cbr\u003eEasy To Use - Laptop programmable ECU includes a variety of base maps that will have you hitting the cruise or track in no time\u003cbr\u003eECU is certified to ISO 8846, SAE J1171 \u0026amp; United States Coast Guard Requirements for Ignition Protection \u0026amp; Fire Resistance\u003cbr\u003eFor a full list of advanced features such as boost, nitrous, water\/meth, individual cylinder control and more click the document icon under the product image!\u003cbr\u003eMore Functionality - Provides significantly more functionality than OEM or other competitive ECUs (boost control, nitrous control, water\/meth injection, plus a host of additional inputs and outputs to control fans, pumps, relays etc.)\u003cbr\u003eKit includes ECU, harness, communication cable, software and and Bosch wideband 02 sensor designed to be used with GM LS1\/LS6 engines with factory GM coils and a 24 tooth crank sensor\u003cbr\u003eSimple Installation - Plug and Play control of GM LS1\/LS6 engines. Just plug the harness into your factory sensors, wire the power and grounds and you are ready to take complete control of your LS engine\u003cbr\u003eECU is fully potted and can be mounted in the engine compartment or interior\u003cbr\u003eSealed automotive and marine grade connectors\u003cbr\u003e1-5 Bar MAP sensor capability\u003cbr\u003eIndustry Leading Self Tuning Fuel Strategy - means less time tuning and more time enjoying the power of your LS vehicle\u003c\/p\u003e","brand":"Holley EFI","offers":[{"title":"Default Title","offer_id":49453344784622,"sku":"HLY-550-602","price":2849.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0819\/9110\/6798\/files\/Screenshot2026-08-20224359.png?v=1787283850"},{"product_id":"hp-efi-ecu-harness-kits-550-620n","title":"HP EFI ECU \u0026 Harness Kits 550-620N","description":"\u003cp\u003eGM LS1\/LS6 (24x crank sensor) with Jetronic\/Minitimer (Bosch type) connectors on injector harness, Includes NTK Oxygen Sensor\u003c\/p\u003e\n\u003cp\u003eFeatures:\u003cbr\u003eECU is certified to ISO 8846, SAE J1171 \u0026amp; United States Coast Guard Requirements for Ignition Protection \u0026amp; Fire Resistance\u003cbr\u003e1-5 Bar MAP sensor capability\u003cbr\u003eEasy To Use - Laptop programmable ECU includes a variety of base maps that will have you hitting the cruise or track in no time\u003cbr\u003eSealed automotive and marine grade connectors\u003cbr\u003eFor a full list of advanced features such as boost, nitrous, water\/meth, individual cylinder control and more click the document icon under the product image!\u003cbr\u003eThe NTK Oxygen Sensor is recommended when using leaded or methanol fuels, high exhaust temperatures and forced induction applications or for highest precision feedback\u003cbr\u003eIdeal For Everything - including stock 5.3L engine swaps or all out, 3,000+ horsepower race cars that need a simple and powerful ECU and harness solution\u003cbr\u003eOptional plug and play hand-held programmer, 5.7\" touchscreen and digital gauges are available for ultimate control and vehicle monitoring\u003cbr\u003eECU is fully potted and can be mounted in the engine compartment or interior\u003cbr\u003eIndustry Leading Self Tuning Fuel Strategy - means less time tuning and more time enjoying the power of your LS vehicle\u003cbr\u003eMore Functionality - Provides significantly more functionality than OEM or other competitive ECUs (boost control, nitrous control, water\/meth injection, plus a host of additional inputs and outputs to control fans, pumps, relays etc.)\u003cbr\u003eSimple Installation - Plug and Play control of GM LS1\/LS6 engines. Just plug the harness into your factory sensors, wire the power and grounds and you are ready to take complete control of your LS engine\u003cbr\u003eKit includes ECU, harness, communication cable, software and and NTK wideband 02 sensor designed to be used with GM LS1\/LS6 engines with factory GM coils and a 24 tooth crank sensor\u003c\/p\u003e","brand":"Holley EFI","offers":[{"title":"Default Title","offer_id":49453349241070,"sku":"HLY-550-602N","price":3099.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0819\/9110\/6798\/files\/Screenshot2026-08-20224803.png?v=1787284093"},{"product_id":"hp-efi-ecu-harness-kits-550-603","title":"HP EFI ECU \u0026 Harness Kits 550-603","description":"\u003cp\u003eGM LS2\/3\/7 (58x crank sensor) with USCAR (EV6 Style) connectors on injector harness, Includes Bosch Oxygen Sensor\u003c\/p\u003e\n\u003cp\u003eFeatures:\u003cbr\u003e1-5 Bar MAP sensor capability\u003cbr\u003eSimple Installation - Plug and Play control of GM LS2\/LS3\/LS7 engines. Just plug the harness into your factory sensors, wire the power and grounds and you are ready to take complete control of your LS engine\u003cbr\u003eECU is fully potted and can be mounted in the engine compartment or interior\u003cbr\u003eIndustry Leading Self Tuning Fuel Strategy - means less time tuning and more time enjoying the power of your LS vehicle\u003cbr\u003eFor a full list of advanced features such as boost, nitrous, water\/meth, individual cylinder control and more click the document icon under the product image!\u003cbr\u003eEasy To Use - Laptop programmable ECU includes a variety of base maps that will have you hitting the cruise or track in no time\u003cbr\u003eECU is certified to ISO 8846, SAE J1171 \u0026amp; United States Coast Guard Requirements for Ignition Protection \u0026amp; Fire Resistance\u003cbr\u003eKit includes ECU, harness, communication cable, software, USCAR (EV6 Style) injector connectors, and Bosch wideband O2 sensor, designed to be used with GM LS2\/LS3\/LS7 engines with factory GM coils and a 58 tooth crank sensor\u003cbr\u003eOptional plug and play hand-held programmer, 5.7\" touch screen and digital gauges are available for ultimate control and vehicle monitoring\u003cbr\u003eSealed automotive and marine grade connectors\u003cbr\u003eMore Functionality - Provides significantly more functionality than OEM or other competitive ECUs (boost control, nitrous control, water\/meth injection, plus a host of additional inputs and outputs to control fans, pumps, relays etc.)\u003cbr\u003eIdeal For Everything - including stock 5.3L engine swaps or all out, 3,000+ horsepower race cars that need a simple and powerful ECU and harness solution\u003c\/p\u003e","brand":"Holley EFI","offers":[{"title":"Default Title","offer_id":49453352026350,"sku":"HLY-550-603","price":2849.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0819\/9110\/6798\/files\/Screenshot2026-08-20225102.png?v=1787284272"},{"product_id":"hp-efi-ecu-harness-kits-550-603n","title":"HP EFI ECU \u0026 Harness Kits 550-603N","description":"\u003cp\u003eGM LS2\/3\/7 (58x crank sensor) with USCAR (EV6 Style) connectors on injector harness, Includes NTK Oxygen Sensor\u003c\/p\u003e\n\u003cp\u003eFeatures:\u003cbr\u003e1-5 Bar MAP sensor capability\u003cbr\u003eECU is certified to ISO 8846, SAE J1171 \u0026amp; United States Coast Guard Requirements for Ignition Protection \u0026amp; Fire Resistance\u003cbr\u003eEasy To Use - Laptop programmable ECU includes a variety of base maps that will have you hitting the cruise or track in no time\u003cbr\u003eMore Functionality - Provides significantly more functionality than OEM or other competitive ECUs (boost control, nitrous control, water\/meth injection, plus a host of additional inputs and outputs to control fans, pumps, relays etc.)\u003cbr\u003eECU is fully potted and can be mounted in the engine compartment or interior\u003cbr\u003eFor a full list of advanced features such as boost, nitrous, water\/meth, individual cylinder control and more click the document icon under the product image!\u003cbr\u003eOptional plug and play hand-held programmer, 5.7\" touch screen and digital gauges are available for ultimate control and vehicle monitoring\u003cbr\u003eSealed automotive and marine grade connectors\u003cbr\u003eIndustry Leading Self Tuning Fuel Strategy - means less time tuning and more time enjoying the power of your LS vehicle\u003cbr\u003eThe NTK Oxygen Sensor is recommended when using leaded or methanol fuels, high exhaust and forced induction applications or for highest precision feedback\u003cbr\u003eSimple Installation - Plug and Play control of GM LS2\/LS3\/LS7 engines. Just plug the harness into your factory sensors, wire the power and grounds and you are ready to take complete control of your LS engine\u003cbr\u003eIdeal For Everything - including stock 5.3L engine swaps or all out, 3,000+ horsepower race cars that need a simple and powerful ECU and harness solution\u003cbr\u003eKit includes ECU, harness, communication cable, software, USCAR (EV6 Style) injector connectors, and NTK wideband O2 sensor, designed to be used with GM LS2\/LS3\/LS7 engines with factory GM coils and a 58 tooth crank sensor\u003c\/p\u003e","brand":"Holley EFI","offers":[{"title":"Default Title","offer_id":49453428572398,"sku":"HLY-550-603N","price":3099.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0819\/9110\/6798\/files\/Screenshot2026-08-20225321.png?v=1787284467"},{"product_id":"hp-efi-ecu-harness-kits-550-604","title":"HP EFI ECU \u0026 Harness Kits 550-604","description":"\u003cp\u003eUniversal V8 Multi-Point Fuel Injection, Includes Bosch Oxygen Sensor\u003c\/p\u003e\n\u003cp\u003eFeatures:\u003cbr\u003eLean or rich safety cutoff\u003cbr\u003e1-5 Bar MAP sensor capability\u003cbr\u003eInternal data-logging standard with a huge 2GB of memory\u003cbr\u003eDedicated fuel and oil pressure inputs\u003cbr\u003eControls both stepper and PWM Idle Air Control (IAC) motors\u003cbr\u003eSpeed density, Alpha-N, or combination fueling strategies\u003cbr\u003eAllows for use of common OEM sensors as well as customer sensor calibration input\u003cbr\u003eWorks with 4, 6, 8 cylinder engines\u003cbr\u003eEight channel Distributorless Ignition (DIS)outputs capable of directly driving “Smart” ignition coils or Holley DIS coils. Will drive 2 wire coils with the addition of PN 554-112 high current coil driver module\u003cbr\u003e4 Programmable high or low Pulse Width Modulated (PWM) outputs and 4 fully configurable inputs can be configured for use\u003cbr\u003eSealed automotive and marine grade connectors\u003cbr\u003eTwo channel knock control sensor Inputs for both one or two wire knock sensors\u003cbr\u003e4 Stage progressive nitrous control\u003cbr\u003eIntegrated Water\/Methanol injection control\u003cbr\u003eEight sequentially driven 8:2 peak and hold injector drivers, capable of driving up to 16 low or high impedance injectors as a standard feature. Multiple staged injector strategies\u003cbr\u003eSelf-tuning fuel table strategy greatly simplifies tuning process\u003cbr\u003eFully featured nitrous control eliminates the need for a separate nitrous controller device\u003cbr\u003eUnique lb\/hr based fueling strategy greatly simplifies and commonizes tuning\u003cbr\u003eECU is fully potted and can be mounted in the engine compartment or interior\u003cbr\u003eAdvanced idle, closed loop, and enrichment strategies allow for very stable operation\u003cbr\u003eIndividual cylinder fuel and spark control allows you to unlock your engine’s potential\u003cbr\u003eUses Holley Water\/Meth solenoids specially designed and calibrated for use with this EFI system to allow the user to enter Water\/Meth flow as a percentage of fuel injector flow for Water\/Meth tuning precision unmatched in the industry\u003cbr\u003e4 Stage nitrous oxide control\u003cbr\u003eFull timing retard\/control configurability per stage based on RPM or time\u003cbr\u003eProgressive control based on time, RPM, or boost, requires part # 554-111\u003cbr\u003eTurbo boost control\u003cbr\u003eIntegrated single channel wide band oxygen sensor control. Works with NTK or Bosch sensors\u003cbr\u003eCan be configured “Wet” or “Dry” with closed loop feedback\u003cbr\u003eIgnition Plug and Play with GM HEI, Ford TFI, magnetic and hall effect trigger, and other ignition systems. New Plug and Play applications in process. Custom settings can be configured to allow many other applications\u003cbr\u003eOptional 5.7” full-color touchscreen LCD allows easy on-the-fly tuning, data-logging or can be used as an easy to see graphical gauge panel\u003c\/p\u003e","brand":"Holley EFI","offers":[{"title":"Default Title","offer_id":49453583401198,"sku":"HLY-550-604","price":2749.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0819\/9110\/6798\/files\/Screenshot2026-08-20225842.png?v=1787284734"},{"product_id":"hp-efi-ecu-harness-kits-550-604n","title":"HP EFI ECU \u0026 Harness Kits 550-604N","description":"\u003cp\u003eUniversal V8 Multi-Point Fuel Injection, Includes NTK Oxygen Sensor\u003c\/p\u003e\n\u003cp\u003eFeatures:\u003cbr\u003eAdvanced idle, closed loop, and enrichment strategies allow for very stable operation\u003cbr\u003eUnique lb\/hr based fueling strategy greatly simplifies and commonizes tuning\u003cbr\u003eIgnition Plug and Play with GM HEI, Ford TFI, magnetic and hall effect trigger, and other ignition systems. New Plug and Play applications in process. Custom settings can be configured to allow many other applications\u003cbr\u003eTwo channel knock control sensor Inputs for both one or two wire knock sensors\u003cbr\u003eSpeed density, Alpha-N, or combination fueling strategies\u003cbr\u003eECU is fully potted and can be mounted in the engine compartment or interior\u003cbr\u003eFully featured nitrous control eliminates the need for a separate nitrous controller device\u003cbr\u003eLean or rich safety cutoff\u003cbr\u003eInternal data-logging standard with a huge 2GB of memory\u003cbr\u003e4 Stage progressive nitrous control\u003cbr\u003eWorks with 4, 6, 8 cylinder engines\u003cbr\u003e4 Stage nitrous oxide control\u003cbr\u003e4 Programmable high or low Pulse Width Modulated (PWM) outputs and 4 fully configurable inputs can be configured for use\u003cbr\u003e1-5 Bar MAP sensor capability\u003cbr\u003eControls both stepper and PWM Idle Air Control (IAC) motors\u003cbr\u003eFull timing retard\/control configurability per stage based on RPM or time\u003cbr\u003eAllows for use of common OEM sensors as well as customer sensor calibration input\u003cbr\u003eSealed automotive and marine grade connectors\u003cbr\u003eIndividual cylinder fuel and spark control allows you to unlock your engine’s potential\u003cbr\u003eCan be configured “Wet” or “Dry” with closed loop feedback\u003cbr\u003eIntegrated Water\/Methanol injection control\u003cbr\u003eIntegrated single channel wide band oxygen sensor control. Works with NTK or Bosch sensors\u003cbr\u003eProgressive control based on time, RPM, or boost, requires part # 554-111\u003cbr\u003eUses Holley Water\/Meth solenoids specially designed and calibrated for use with this EFI system to allow the user to enter Water\/Meth flow as a percentage of fuel injector flow for Water\/Meth tuning precision unmatched in the industry\u003cbr\u003eTurbo boost control\u003cbr\u003eEight channel Distributorless Ignition (DIS)outputs capable of directly driving “Smart” ignition coils or Holley DIS coils. Will drive 2 wire coils with the addition of PN 554-112 high current coil driver module\u003cbr\u003eDedicated fuel and oil pressure inputs\u003cbr\u003eSelf-tuning fuel table strategy greatly simplifies tuning process\u003cbr\u003eOptional 5.7” full-color touchscreen LCD allows easy on-the-fly tuning, data-logging or can be used as an easy to see graphical gauge panel\u003cbr\u003eEight sequentially driven 8:2 peak and hold injector drivers, capable of driving up to 16 low or high impedance injectors as a standard feature. Multiple staged injector strategies\u003c\/p\u003e","brand":"Holley EFI","offers":[{"title":"Default Title","offer_id":49453696418030,"sku":"HLY-550-604N","price":2749.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0819\/9110\/6798\/files\/Screenshot2026-08-20230124.png?v=1787284896"},{"product_id":"hp-efi-ecu-harness-kits-550-605","title":"HP EFI ECU \u0026 Harness Kits 550-605","description":"\u003cp\u003eUnterminated Universal Harness, Includes Bosch Oxygen Sensor\u003c\/p\u003e\n\u003cp\u003eFeatures:\u003cbr\u003e1-5 Bar MAP sensor capability\u003cbr\u003eFull timing retard\/control configurability per stage based on RPM or time\u003cbr\u003eOption for VE based fueling strategy\u003cbr\u003e4 Stage nitrous oxide control\u003cbr\u003eECU is fully potted and can be mounted in the engine compartment or interior\u003cbr\u003eDedicated fuel and oil pressure inputs\u003cbr\u003eIntegrated single channel wide band oxygen sensor control. Works with NTK or Bosch sensors\u003cbr\u003eCustom settings can be configured to allow many other applications\u003cbr\u003eIgnition Plug and Play with GM 24x and 58x LSx engines, GM HEI, Ford TFI, magnetic and hall effect trigger, and other ignition systems. New Plug and Play applications in process.\u003cbr\u003eFully featured nitrous control eliminates the need for a separate nitrous controller device\u003cbr\u003eEight channel Distributorless Ignition (DIS)outputs capable of directly driving “Smart” ignition coils or Holley DIS coils. Will drive 2 wire coils with the addition of PN 554-112 high current coil driver module\u003cbr\u003eConfigurable User Password Protection\u003cbr\u003eWorks with 4, 6, 8 cylinder engines\u003cbr\u003eFuel Map and Learn Function Smoothing\u003cbr\u003eFEATURES\u003cbr\u003ePlug and Play control of factory GM 24x and 58x LSx engines\u003cbr\u003eInternal data-logging standard with a huge 2GB of memory\u003cbr\u003eTwo channel knock control sensor Inputs for both one or two wire knock sensors\u003cbr\u003eProgressive control based on time, RPM, or boost, requires part # 554-111\u003cbr\u003eIntegrated Boost Control - Boost vs Time, Boost vs Gear (Time or RPM), Boost vs RPM, Boost vs Speed, Launch control. Boost launch builder, Over-boost safeties, Boost scramble\u003cbr\u003eSpeed density, Alpha-N, or combination fueling strategies\u003cbr\u003eLean or rich safety cutoff\u003cbr\u003eData Logger. Scalable axes, Smoothing, Multiple graph view ability, Pre-defined notes fields and many more\u003cbr\u003eSealed automotive and marine grade connectors\u003cbr\u003eIntegrated Water\/Methanol injection control\u003cbr\u003eOptional 5.7” full-color touchscreen LCD allows easy on-the-fly tuning,data-logging or can be used as an easy to see graphical gauge panel\u003cbr\u003eAllows for use of common OEM sensors as well as customer sensor calibration input\u003cbr\u003e4 Programmable high or low Pulse Width Modulated (PWM) outputs and 4 fully configurable inputs can be configured for use\u003cbr\u003eCan be configured “Wet” or “Dry” with closed loop feedback\u003cbr\u003eNEW V2 SOFTWARE FEATURES\u003cbr\u003eControls both stepper and PWM Idle Air Control (IAC) motors\u003cbr\u003eTurbo boost control\u003cbr\u003eAdvanced idle, closed loop, and enrichment strategies allow for very stable operation\u003cbr\u003eEight sequentially driven 8:2 peak and hold injector drivers, capable of driving up to 16 low or high impedance injectors as a standard feature. Multiple staged injector strategies\u003cbr\u003e“Quick Start” ignition and fueling strategy for LS x Engines\u003cbr\u003e“Quick Start” fueling for all engines\u003cbr\u003eUnique lb\/hr based fueling strategy greatly simplifies and commonizes tuning\u003cbr\u003eFully Configurable lap top Gauge Panel\u003cbr\u003eStrip Chart Real-Time Data Viewer\u003cbr\u003e4 Stage progressive nitrous control\u003cbr\u003eTraction Control - Power reduction via timing, nitrous percentage or boost (Requires Davis Technologies Holley Module)\u003cbr\u003eUses Holley Water\/Meth solenoids specially designed and calibrated for use with this EFI system to allow the user to enter Water\/Meth flow as a percentage of fuel injector flow for Water\/Meth tuning precision unmatched in the industry\u003cbr\u003eSelf-tuning fuel table strategy greatly simplifies tuning process\u003cbr\u003eIndividual cylinder fuel and spark control allows you to unlock your engine’s potential\u003c\/p\u003e","brand":"Holley EFI","offers":[{"title":"Default Title","offer_id":49453828112622,"sku":"HLY-550-605","price":2749.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0819\/9110\/6798\/files\/Screenshot2026-08-20230419.png?v=1787285075"},{"product_id":"hp-efi-ecu-harness-kits-550-605n","title":"HP EFI ECU \u0026 Harness Kits 550-605N","description":"\u003cp\u003eUnterminated Universal Harness, Includes NTK Oxygen Sensor\u003c\/p\u003e","brand":"Holley EFI","offers":[{"title":"Default Title","offer_id":49509503860974,"sku":"HLY-550-605N","price":2999.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0819\/9110\/6798\/files\/Screenshot2026-08-27223716.png?v=1787888253"},{"product_id":"holley-efi-8-channel-can-egt-kit-554-186","title":"Holley EFI 8 Channel CAN EGT Kit 554-186","description":"\u003cdiv class=\"full_description\"\u003eIntroducing the Holley EFI 8 Channel CANBus EGT Kit. Exhaust Gas Temperature data is critical information when your engine tune up is on the ragged edge. Knowing the exhaust temperature of each cylinder can help you identify potential horsepower left on the table, or pin point any weak links in your max effort race engine. You can also use this data to quickly identify a potential ignition misfire, or stuck injector! The included sensors are designed to work with any engine combination, with an open reinforced tip for the fastest response rate, and improved shielding. The probes come in 4 different lengths ensuring a clean looking installation. The included 316 stainless steel bungs feature a built in step, making bung installation as easy as possible. Everything needed to upgrade your exhaust system is included, such as 1\/4\" 316 Stainless Steel EGT Bungs, 8 EGT Sensors, and the 8 Channel CANbus EGT controller!\u003c\/div\u003e\n\u003ch3\u003eFeatures:\u003c\/h3\u003e\n\u003cul class=\"productpage_list\"\u003e\n\u003cli\u003eCompatible with HP or Dominator EFI, and Terminator X EFI.\u003c\/li\u003e\n\u003cli\u003ePlug and Play 8 Channel CAN EGT Module, for a quick and easy installation\u003c\/li\u003e\n\u003cli\u003eHigh Quality ¼” Stepped Stainless Steel EGT Weld Bungs\u003c\/li\u003e\n\u003cli\u003e8x- Robust ¼” EGT Probes, designed to withstand the extreme cylinder pressures\u003c\/li\u003e\n\u003cli\u003e4’ CAN Extension Harness\u003c\/li\u003e\n\u003cli\u003e8x Analog output wires, to be used with non-Holley EFI installations\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Holley EFI","offers":[{"title":"Default Title","offer_id":49520521052398,"sku":"HLY-554-186","price":1599.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0819\/9110\/6798\/files\/Screenshot2026-08-31225603.png?v=1788234976"},{"product_id":"unterminated-15-flying-lead-main-harness-558-126","title":"Unterminated 15' Flying Lead Main Harness 558-126","description":"\u003cdiv class=\"full_description\"\u003eThe unterminated main harness comes with both J1A and J1B connectors full terminated with 15' of flying lead wiring.\u003c\/div\u003e\n\u003ch3\u003eFeatures:\u003c\/h3\u003e\n\u003cul class=\"productpage_list\"\u003e\n\u003cli\u003eUnterminated\u003c\/li\u003e\n\u003cli\u003e15’ long flying lead harness\u003c\/li\u003e\n\u003cli\u003e60 Holley Crimped Wires (57x 20 ga, 3x 18 ga)\u003c\/li\u003e\n\u003cli\u003e30 optional plug seals\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Holley EFI","offers":[{"title":"Default Title","offer_id":49520525312238,"sku":"HLY-558-126","price":449.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0819\/9110\/6798\/files\/Screenshot2026-08-31230224.png?v=1788235357"},{"product_id":"hp-efi-ecu-harness-kits-550-607","title":"HP EFI ECU \u0026 Harness Kits 550-607","description":"\u003cp\u003e\u003cspan\u003eGM LS2\/3\/7 (58x crank sensor) with Jetronic\/Minitimer (Bosch type) connectors on injector harness (fits Holley 522-xxx injectors), Includes Bosch Oxygen Sensor\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cdiv class=\"full_description\"\u003eLooking for a plug and play kit for your GM LS engine? The HP ECU allows you to accurately control the fuel and ignition of your engine plus much more. Got a stock LS engine? Simply download a base map and you're on your way. Got a turbocharged, nitrous fed LS engine on water\/meth? This HP EFI kit can control that too!\u003c\/div\u003e\n\u003ch3\u003eFeatures:\u003c\/h3\u003e\n\u003cul class=\"productpage_list\"\u003e\n\u003cli\u003eECU is certified to ISO 8846, SAE J1171 \u0026amp; United States Coast Guard Requirements for Ignition Protection \u0026amp; Fire Resistance\u003c\/li\u003e\n\u003cli\u003eFor a full list of advanced features such as boost, nitrous, water\/meth, individual cylinder control and more click the document icon under the product image!\u003c\/li\u003e\n\u003cli\u003eIndustry Leading Self Tuning Fuel Strategy - means less time tuning and more time enjoying the power of your LS vehicle\u003c\/li\u003e\n\u003cli\u003eOptional plug and play hand-held programmer, 5.7\" touch screen and digital gauges are available for ultimate control and vehicle monitoring\u003c\/li\u003e\n\u003cli\u003eECU is fully potted and can be mounted in the engine compartment or interior\u003c\/li\u003e\n\u003cli\u003eKit includes ECU, harness, communication cable, software, Jetronic\/Minitimer (Bosch style) injector connectors, and Bosch wideband O2 sensor, designed to be used with GM LS2\/LS3\/LS7 engines with factory GM coils and a 58 tooth crank sensor\u003c\/li\u003e\n\u003cli\u003eSimple Installation - Plug and Play control of GM LS2\/LS3\/LS7 engines. Just plug the harness into your factory sensors, wire the power and grounds and you are ready to take complete control of your LS engine\u003c\/li\u003e\n\u003cli\u003eSealed automotive and marine grade connectors\u003c\/li\u003e\n\u003cli\u003e1-5 Bar MAP sensor capability\u003c\/li\u003e\n\u003cli\u003eIdeal For Everything - including stock 5.3L engine swaps or all out, 3,000+ horsepower race cars that need a simple and powerful ECU and harness solution\u003c\/li\u003e\n\u003cli\u003eEasy To Use - Laptop programmable ECU includes a variety of base maps that will have you hitting the cruise or track in no time\u003c\/li\u003e\n\u003cli\u003eMore Functionality - Provides significantly more functionality than OEM or other competitive ECUs (boost control, nitrous control, water\/meth injection, plus a host of additional inputs and outputs to control fans, pumps, relays etc.)\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Holley EFI","offers":[{"title":"Default Title","offer_id":49537749876974,"sku":"HLY-550-607","price":2849.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0819\/9110\/6798\/files\/Screenshot2026-09-04152843.png?v=1788553738"},{"product_id":"hp-efi-ecu-harness-kits-550-607n","title":"HP EFI ECU \u0026 Harness Kits 550-607N","description":"\u003cp\u003e\u003cspan\u003eGM LS2\/3\/7 (58x crank sensor) with Jetronic\/Minitimer (Bosch type) connectors on injector harness (fits Holley 522-xxx injectors), Includes NTK Oxygen Sensor\u003c\/span\u003e\u003c\/p\u003e\n\u003cdiv class=\"full_description\"\u003eLooking for a plug and play kit for your GM LS engine? The HP ECU allows you to accurately control the fuel and ignition of your engine plus much more. Got a stock LS engine? Simply download a base map and you're on your way. Got a turbocharged, nitrous fed LS engine on water\/meth? This HP EFI kit can control that too!\u003c\/div\u003e\n\u003ch3\u003eFeatures:\u003c\/h3\u003e\n\u003cul class=\"productpage_list\"\u003e\n\u003cli\u003eIdeal For Everything - including stock 5.3L engine swaps or all out, 3,000+ horsepower race cars that need a simple and powerful ECU and harness solution\u003c\/li\u003e\n\u003cli\u003eEasy To Use - Laptop programmable ECU includes a variety of base maps that will have you hitting the cruise or track in no time\u003c\/li\u003e\n\u003cli\u003eKit includes ECU, harness, communication cable, software, Jetronic\/Minitimer (Bosch style) injector connectors, and NTK wideband O2 sensor, designed to be used with GM LS2\/LS3\/LS7 engines with factory GM coils and a 58 tooth crank sensor\u003c\/li\u003e\n\u003cli\u003eFor a full list of advanced features such as boost, nitrous, water\/meth, individual cylinder control and more click the document icon under the product image!\u003c\/li\u003e\n\u003cli\u003eMore Functionality - Provides significantly more functionality than OEM or other competitive ECUs (boost control, nitrous control, water\/meth injection, plus a host of additional inputs and outputs to control fans, pumps, relays etc.)\u003c\/li\u003e\n\u003cli\u003eThe NTK Oxygen Sensor is recommended when using leaded or methanol fuels, high exhaust and forced induction applications or for highest precision feedback\u003c\/li\u003e\n\u003cli\u003e1-5 Bar MAP sensor capability\u003c\/li\u003e\n\u003cli\u003eOptional plug and play hand-held programmer, 5.7\" touch screen and digital gauges are available for ultimate control and vehicle monitoring\u003c\/li\u003e\n\u003cli\u003eIndustry Leading Self Tuning Fuel Strategy - means less time tuning and more time enjoying the power of your LS vehicle\u003c\/li\u003e\n\u003cli\u003eECU is certified to ISO 8846, SAE J1171 \u0026amp; United States Coast Guard Requirements for Ignition Protection \u0026amp; Fire Resistance\u003c\/li\u003e\n\u003cli\u003eSealed automotive and marine grade connectors\u003c\/li\u003e\n\u003cli\u003eECU is fully potted and can be mounted in the engine compartment or interior\u003c\/li\u003e\n\u003cli\u003eSimple Installation - Plug and Play control of GM LS2\/LS3\/LS7 engines. Just plug the harness into your factory sensors, wire the power and grounds and you are ready to take complete control of your LS engine\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Holley EFI","offers":[{"title":"Default Title","offer_id":49537751318766,"sku":"HLY-550-607N","price":3099.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0819\/9110\/6798\/files\/Screenshot2026-09-04153347.png?v=1788554037"},{"product_id":"terminator-ls-mpfi-kit-550-613","title":"Terminator LS MPFI Kit 550-613","description":"\u003cdiv class=\"full_description\"\u003eGet all the great features of Terminator self-tuning EFI in a bolt-on system for GM's popular LS engines! The 550-613 kit controls fuel, spark, drive-by-wire and 4L60\/4L80E transmissions through the Terminator's new 3.5\" touchscreen! Install, answer a few basic questions and drive. No laptop required!\u003c\/div\u003e\n\u003ch3\u003eFeatures:\u003c\/h3\u003e\n\u003cul class=\"productpage_list\"\u003e\n\u003cli\u003eFor GM LS2\/3 engines and 2007 to current 4.8\/5.3\/6.0 truck engines with 58x crank reluctor, drive-by-wire, and 4L60\/4L80E transmissions\u003c\/li\u003e\n\u003cli\u003eKit includes everything you need to control your stock or mild LS\u003c\/li\u003e\n\u003cli\u003eBosch wideband oxygen sensor included\u003c\/li\u003e\n\u003cli\u003eControls fuel, spark, drive-by-wire, and 4L60\/4L80E transmissions\u003c\/li\u003e\n\u003cli\u003ePre-calibrated for no-hassle installation and tuning\u003c\/li\u003e\n\u003cli\u003eFully adjustable through included 3.5” full color touchscreen\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Holley EFI","offers":[{"title":"Default Title","offer_id":49537757020398,"sku":"HLY-550-613","price":4649.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0819\/9110\/6798\/files\/Screenshot2026-09-04154549.png?v=1788554801"},{"product_id":"terminator-ls-mpfi-kit-550-614","title":"Terminator LS MPFI Kit 550-614","description":"\u003cp\u003eGet all the great features of Terminator self-tuning EFI in a bolt-on system for GM's popular LS engines! The 550-614 kit controls fuel and spark through the Terminator's new 3.5\" touchscreen! Install, answer a few basic questions and drive. No laptop required!\u003cbr\u003eFeatures:\u003cbr\u003eFor 1997 to 2007 4.8\/5.3\/6.0 truck engines with 24x crank reluctor\u003cbr\u003eKit includes everything you need to control your stock or mild LS\u003cbr\u003eBosch wideband oxygen sensor included\u003cbr\u003eControls fuel and spark\u003cbr\u003ePre-calibrated for no-hassle installation and tuning\u003cbr\u003eFully adjustable through included 3.5” full color touchscreen\u003c\/p\u003e","brand":"Holley EFI","offers":[{"title":"Default Title","offer_id":49537758757102,"sku":"HLY-550-614","price":2949.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0819\/9110\/6798\/files\/Screenshot2026-09-04154847.png?v=1788554936"},{"product_id":"terminator-ls-mpfi-kit-550-615","title":"Terminator LS MPFI Kit 550-615","description":"\u003cdiv class=\"full_description\"\u003eGet all the great features of Terminator self-tuning EFI in a bolt-on system for GM's popular LS engines! The 550-615 kit controls fuel, spark, and drive-by-wire through the Terminator's new 3.5\" touchscreen! Install, answer a few basic questions and drive. No laptop required!\u003c\/div\u003e\n\u003ch3\u003eFeatures:\u003c\/h3\u003e\n\u003cul class=\"productpage_list\"\u003e\n\u003cli\u003eFor 1997 to 2007 4.8\/5.3\/6.0 truck engines with 24x crank reluctor and drive-by-wire\u003c\/li\u003e\n\u003cli\u003eKit includes everything you need to control your stock or mild LS\u003c\/li\u003e\n\u003cli\u003eBosch wideband oxygen sensor included\u003c\/li\u003e\n\u003cli\u003eControls fuel, spark, and drive-by-wire\u003c\/li\u003e\n\u003cli\u003ePre-calibrated for no-hassle installation and tuning\u003c\/li\u003e\n\u003cli\u003eFully adjustable through included 3.5” full color touchscreen\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Holley EFI","offers":[{"title":"Default Title","offer_id":49537765671150,"sku":"HLY-550-615","price":4349.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0819\/9110\/6798\/files\/Screenshot2026-09-04155344.png?v=1788555234"},{"product_id":"hp-efi-ecu-harness-kits-550-616","title":"HP EFI ECU \u0026 Harness Kits 550-616","description":"\u003cdiv class=\"full_description\"\u003eLooking for a plug and play kit for your Ford Modular engine? The HP ECU allows you to accurately control the fuel and ignition of your engine plus much more! Is your cam too wild for a MAF? Power adders? You name it, and Holley EFI can handle it.\u003c\/div\u003e\n\u003ch3\u003eFeatures:\u003c\/h3\u003e\n\u003cul class=\"productpage_list\"\u003e\n\u003cli\u003eDesigned specifically for 1999-2004 Ford Modular 2 Valve Engines\u003c\/li\u003e\n\u003cli\u003ePlug and play with factory sensors, Crank, Cam, TPS, Coolant Temp, etc\u003c\/li\u003e\n\u003cli\u003ePlug and play with factory actuators, Coils, Injectors, IAC\u003c\/li\u003e\n\u003cli\u003eConnectors for Holley Fuel Pressure and Oil Pressure sensors\u003c\/li\u003e\n\u003cli\u003eConnectors for expanded Inputs and Outputs\u003c\/li\u003e\n\u003cli\u003eComplete plug and play kit includes HP ECU, Bosch Wideband O2 sensor, MAP sensor, Coil Drivers and all necessary Harnesses\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Holley EFI","offers":[{"title":"Default Title","offer_id":49537776419054,"sku":"HLY-550-616","price":3299.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0819\/9110\/6798\/files\/Screenshot2026-09-04155608.png?v=1788555407"}],"url":"https:\/\/elmosspeedshop.com\/collections\/ecu-harness-kits.oembed","provider":"Elmo's Speed Shop","version":"1.0","type":"link"}