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    Sale!

    Holley EFI Unterminated Universal Harness, Includes Bosch Oxygen Sensor 550-605

    Vendor: Holley EFI
    SKU: GVMR_550-605
    Save $327
    Sale Price $2,609.95 Regular Price $2,936.95
    Fast Fulfillment: In-stock parts typically ship same day or next business day.
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    Looking for a plug and play alternative for your stock or built late model factory EFI engine? How about a replacement ECU for your older Holley C950? Holley has you covered. HP EFI ECU and harness kits are designed to be used with popular factory EFI engines as an alternative to the factory ECU and harness or as a replacement for your C950 ECU. The HP allows you to accurately control the fuel and ignition of your engine along with additional controls for nitrous, boost or water meth.


    Holley EFI Unterminated Universal Harness, Includes Bosch Oxygen Sensor 550-605


    Specifications:

    10429 Yes
    10431 Yes
    Brand Holley EFI
    10423 Yes
    Category Air and Fuel Delivery
    10438 Yes
    10430 Yes
    10442 Yes
    10418 Yes
    10428 Yes
    Emission Code 3
    10433 Yes
    7246 No
    10417 No
    906 No
    10425 No
    8922 No
    3390 Performance
    10422 Yes
    Ignition Type Coil - (No Timing Control), Ford TFI, GM HEI Small Cap, Holley Dual Sync Distributor
    10432 Yes
    Injector Connector Jetronic / Minitimer (Bosch)
    9780 No
    10427 Yes
    10420 Yes
    part type Fuel Injection Conversion Kit
    Product Type HP EFI Kit
    10421 Yes
    10434 Yes
    Sub Category Service Kits
    918 No
    10426 Yes
    10435 Yes
    Warning California Proposition 65
    10419 Yes
    10429 Yes
    10431 Yes
    Brand Holley EFI
    10423 Yes
    Category Air and Fuel Delivery
    10438 Yes
    10430 Yes
    10442 Yes
    10418 Yes
    10428 Yes
    Emission Code 3
    10433 Yes
    7246 No
    10417 No
    906 No
    10425 No
    8922 No
    3390 Performance
    10422 Yes
    Ignition Type Coil - (No Timing Control), Ford TFI, GM HEI Small Cap, Holley Dual Sync Distributor
    10432 Yes
    Injector Connector Jetronic / Minitimer (Bosch)
    9780 No
    10427 Yes
    10420 Yes
    part type Fuel Injection Conversion Kit
    Product Type HP EFI Kit
    10421 Yes
    10434 Yes
    Sub Category Service Kits
    918 No
    10426 Yes
    10435 Yes
    Warning California Proposition 65
    10419 Yes
    Description_ABR ERF Kit
    Description_SHO Harness Kit
    Description_INV HP ECU AND UNTERMINATED HARNESS KIT
    Description_ASC ECU is certified to ISO 8846, SAE J1171 & United States Coast Guard Requirements for Ignition Protection & Fire Resistance. Holley HP EFI systems are equipped with 4 programmable inputs and 4 programmable outputs that are ideal for most vehicles with a single power adder. This feature allows the user to configure the system to support a wide range of controls including boost control, progressive nitrous, water/meth injection, speed inputs, fuel pump control, AC inputs, timing retard inputs and various other uses. When selecting an ECU, users need to ensure their planned controls can be run with the 4 inputs and 4 outputs as certain combinations may use more I/Os than are available. If more I/Os are required, users should choose the Dominator VMS. Software and firmware updates can be downloaded here for free.
    Description_DES HP EFI ECU & Harness Kits
    Description_EXT Unterminated Universal Harness, Includes Bosch Oxygen Sensor
    Description_MKT Looking for a plug and play alternative for your stock or built late model factory EFI engine? How about a replacement ECU for your older Holley C950? Holley has you covered. HP EFI ECU and harness kits are designed to be used with popular factory EFI engines as an alternative to the factory ECU and harness or as a replacement for your C950 ECU. The HP allows you to accurately control the fuel and ignition of your engine along with additional controls for nitrous, boost or water meth.
    Description_FAB 1-5 Bar MAP sensor capability
    Description_FAB Full timing retard/control configurability per stage based on RPM or time
    Description_FAB Option for VE based fueling strategy
    Description_FAB 4 Stage nitrous oxide control
    Description_FAB ECU is fully potted and can be mounted in the engine compartment or interior
    Description_FAB Dedicated fuel and oil pressure inputs
    Description_FAB Integrated single channel wide band oxygen sensor control. Works with NTK or Bosch sensors
    Description_FAB Custom settings can be configured to allow many other applications
    Description_FAB Ignition 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.
    Description_FAB Fully featured nitrous control eliminates the need for a separate nitrous controller device
    Description_FAB Eight 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
    Description_FAB Configurable User Password Protection
    Description_FAB Works with 4, 6, 8 cylinder engines
    Description_FAB Fuel Map and Learn Function Smoothing
    Description_FAB FEATURES
    Description_FAB Plug and Play control of factory GM 24x and 58x LSx engines
    Description_FAB Internal data-logging standard with a huge 2GB of memory
    Description_FAB Two channel knock control sensor Inputs for both one or two wire knock sensors
    Description_FAB Progressive control based on time, RPM, or boost, requires part # 554-111
    Description_FAB Integrated 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
    Description_FAB Speed density, Alpha-N, or combination fueling strategies
    Description_FAB Lean or rich safety cutoff
    Description_FAB Data Logger. Scalable axes, Smoothing, Multiple graph view ability, Pre-defined notes fields and many more
    Description_FAB Sealed automotive and marine grade connectors
    Description_FAB Integrated water/methanol injection control
    Description_FAB Optional 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
    Description_FAB Allows for use of common OEM sensors as well as customer sensor calibration input
    Description_FAB 4 Programmable high or low Pulse Width Modulated (PWM) outputs and 4 fully configurable inputs can be configured for use
    Description_FAB Can be configured “Wet” or “Dry” with closed loop feedback
    Description_FAB NEW V2 SOFTWARE FEATURES
    Description_FAB Controls both stepper and PWM Idle Air Control (IAC) motors
    Description_FAB Turbo boost control
    Description_FAB Advanced idle, closed loop, and enrichment strategies allow for very stable operation
    Description_FAB Eight 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
    Description_FAB “Quick Start” ignition and fueling strategy for LS x Engines
    Description_FAB “Quick Start” fueling for all engines
    Description_FAB Unique lb/hr based fueling strategy greatly simplifies and commonizes tuning
    Description_FAB Fully Configurable lap top Gauge Panel
    Description_FAB Strip Chart Real-Time Data Viewer
    Description_FAB 4 Stage progressive nitrous control
    Description_FAB Traction Control - Power reduction via timing, nitrous percentage or boost (Requires Davis Technologies Holley Module)
    Description_FAB Uses 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
    Description_FAB Self-tuning fuel table strategy greatly simplifies tuning process
    Description_FAB Individual cylinder fuel and spark control allows you to unlock your engine’s potential
    Description_ABR ERF Kit
    Description_SHO Harness Kit
    Description_INV HP ECU AND UNTERMINATED HARNESS KIT
    Description_ASC ECU is certified to ISO 8846, SAE J1171 & United States Coast Guard Requirements for Ignition Protection & Fire Resistance. Holley HP EFI systems are equipped with 4 programmable inputs and 4 programmable outputs that are ideal for most vehicles with a single power adder. This feature allows the user to configure the system to support a wide range of controls including boost control, progressive nitrous, water/meth injection, speed inputs, fuel pump control, AC inputs, timing retard inputs and various other uses. When selecting an ECU, users need to ensure their planned controls can be run with the 4 inputs and 4 outputs as certain combinations may use more I/Os than are available. If more I/Os are required, users should choose the Dominator VMS. Software and firmware updates can be downloaded here for free.
    Description_DES HP EFI ECU & Harness Kits
    Description_EXT Unterminated Universal Harness, Includes Bosch Oxygen Sensor
    Description_MKT Looking for a plug and play alternative for your stock or built late model factory EFI engine? How about a replacement ECU for your older Holley C950? Holley has you covered. HP EFI ECU and harness kits are designed to be used with popular factory EFI engines as an alternative to the factory ECU and harness or as a replacement for your C950 ECU. The HP allows you to accurately control the fuel and ignition of your engine along with additional controls for nitrous, boost or water meth.
    Description_FAB 1-5 Bar MAP sensor capability
    Description_FAB Full timing retard/control configurability per stage based on RPM or time
    Description_FAB Option for VE based fueling strategy
    Description_FAB 4 Stage nitrous oxide control
    Description_FAB ECU is fully potted and can be mounted in the engine compartment or interior
    Description_FAB Dedicated fuel and oil pressure inputs
    Description_FAB Integrated single channel wide band oxygen sensor control. Works with NTK or Bosch sensors
    Description_FAB Custom settings can be configured to allow many other applications
    Description_FAB Ignition 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.
    Description_FAB Fully featured nitrous control eliminates the need for a separate nitrous controller device
    Description_FAB Eight 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
    Description_FAB Configurable User Password Protection
    Description_FAB Works with 4, 6, 8 cylinder engines
    Description_FAB Fuel Map and Learn Function Smoothing
    Description_FAB FEATURES
    Description_FAB Plug and Play control of factory GM 24x and 58x LSx engines
    Description_FAB Internal data-logging standard with a huge 2GB of memory
    Description_FAB Two channel knock control sensor Inputs for both one or two wire knock sensors
    Description_FAB Progressive control based on time, RPM, or boost, requires part # 554-111
    Description_FAB Integrated 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
    Description_FAB Speed density, Alpha-N, or combination fueling strategies
    Description_FAB Lean or rich safety cutoff
    Description_FAB Data Logger. Scalable axes, Smoothing, Multiple graph view ability, Pre-defined notes fields and many more
    Description_FAB Sealed automotive and marine grade connectors
    Description_FAB Integrated water/methanol injection control
    Description_FAB Optional 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
    Description_FAB Allows for use of common OEM sensors as well as customer sensor calibration input
    Description_FAB 4 Programmable high or low Pulse Width Modulated (PWM) outputs and 4 fully configurable inputs can be configured for use
    Description_FAB Can be configured “Wet” or “Dry” with closed loop feedback
    Description_FAB NEW V2 SOFTWARE FEATURES
    Description_FAB Controls both stepper and PWM Idle Air Control (IAC) motors
    Description_FAB Turbo boost control
    Description_FAB Advanced idle, closed loop, and enrichment strategies allow for very stable operation
    Description_FAB Eight 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
    Description_FAB “Quick Start” ignition and fueling strategy for LS x Engines
    Description_FAB “Quick Start” fueling for all engines
    Description_FAB Unique lb/hr based fueling strategy greatly simplifies and commonizes tuning
    Description_FAB Fully Configurable lap top Gauge Panel
    Description_FAB Strip Chart Real-Time Data Viewer
    Description_FAB 4 Stage progressive nitrous control
    Description_FAB Traction Control - Power reduction via timing, nitrous percentage or boost (Requires Davis Technologies Holley Module)
    Description_FAB Uses 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
    Description_FAB Self-tuning fuel table strategy greatly simplifies tuning process
    Description_FAB Individual cylinder fuel and spark control allows you to unlock your engine’s potential


    Shipping Policy

    Last Updated: June 2026

    We're committed to getting your order to you as quickly and transparently as possible. Here's everything you need to know about how we ship.

    Order Processing Time

    In-stock orders are typically processed and shipped within 1–2 business days of receiving payment, unless otherwise noted on the product page.

    Orders placed on weekends or holidays will be processed on the next business day.

    Processing times are estimates and may vary during periods of high order volume, severe weather events, holidays, or circumstances beyond our control.

    Backordered Items & ETA Listings

    Some listings display an estimated ship date (ETA). These items are not in stock at the time of order and will not ship immediately.

    ETAs are provided by manufacturers and suppliers and are not guaranteed. Ship dates may change without notice.

    By placing an order for an ETA listing, you acknowledge and agree to the estimated timeframe displayed on the product page.

    If you need to cancel a backordered item, please refer to our Refund Policy for applicable cancellation fees.

    Order Cancellations

    Once an order is placed, cancellations are not guaranteed, as orders are sent to fulfillment quickly.

    If you need to cancel an order, contact us immediately at sales@berryperformancesales.com.

    If a cancellation is possible, applicable processing fees may apply in accordance with our Refund Policy.

    Orders that have already shipped cannot be cancelled and must go through our standard return process.

    Shipping Costs

    Shipping costs are calculated at checkout based on the shipping method selected, package weight and dimensions, and destination address.

    Available shipping options and costs will be displayed before you complete your purchase.

    Estimated Delivery Times

    Domestic orders typically arrive within 1–7 business days after shipment, depending on your location and the carrier.

    Delivery times are estimates only and are not guaranteed.

    Delays due to weather, carrier volume, customs processing, labor disruptions, or other circumstances beyond our control may occur.

    Tracking Information

    Once your order ships, you will receive a confirmation email with tracking information.

    If your tracking has not updated within 48 hours of receiving your shipping confirmation, please contact us.

    Shipping Address

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    Failure to note damage or shortages at the time of delivery may limit or void the ability to file a freight damage claim.

    If your freight shipment arrives damaged, contact us within 48 hours of delivery.

    Lost or Stolen Packages

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    • Check around your property and with neighbors
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    If the issue remains unresolved, contact us within 5 business days of the marked delivery date.

    We will work with you and the carrier to investigate the issue.

    Berry Performance Sales is not responsible for packages confirmed as delivered by the carrier or for packages lost or stolen after delivery.

    Refused or Undeliverable Shipments

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    We ship internationally.

    International orders may require a custom shipping quote prior to purchase.

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    • Your country and full delivery address
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    International customers are responsible for all customs duties, taxes, brokerage fees, import fees, and other charges imposed by their local government.

    These charges are not included in shipping quotes and are non-refundable.

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    Email: sales@berryperformancesales.com

    Berry Performance Sales reserves the right to update this policy at any time. Changes take effect immediately upon posting. It is the customer's responsibility to review the current policy at the time of purchase.

    Return Policy

    Last Updated: June 2026

    We want you to love what you ordered. If something isn't right, here's everything you need to know.

    30-Day Return Window

    You have 30 days from the date your order is shipped to initiate a return. After this window, we are unable to accept returns.

    We do not offer exchanges. All approved returns are refunded according to the terms below.

    How to Initiate a Return

    To request a return, contact us at sales@berryperformancesales.com with your order number and reason for return.

    All returns must be approved by our team before any item is shipped back to us.

    Once your return has been approved, your item must be shipped within 10 calendar days of approval. Valid tracking information must be provided upon request.

    Items shipped without prior approval, without verifiable tracking information upon request, or outside this window may be refused and returned to sender at the customer's expense.

    Return Conditions

    To be eligible for a return, items must be:

    • Unused and in original condition
    • In original packaging
    • Complete with all original parts, hardware, manuals, accessories, and promotional items

    The following items are not eligible for return:

    • Custom-ordered products
    • Programmers and tuners, unless brand new and factory sealed. Any unit that has been connected to a vehicle, registered, or used to flash a tune is not returnable, regardless of packaging condition
    • Open Box listings
    • Installed, modified, painted, coated, welded, cut, or otherwise used products
    • Items marked as Clearance, Closeout, or Final Sale

    Products sold as kits, complete systems, or bundled packages must be returned in their entirety. Partial returns are not accepted.

    Items that include promotional products, discounts, or free gifts must be returned with all included items. If any promotional item is not returned, its retail value may be deducted from the refund.

    We strongly recommend test-fitting all parts before installation, painting, coating, or modification.

    Labor costs, installation fees, tuning expenses, diagnostic charges, rental vehicles, towing fees, downtime, or any other incidental or consequential costs are not reimbursable under any circumstances.

    If you're unsure whether your item qualifies for return, contact us before purchasing.

    Once we receive your return, we will inspect the item before processing any refund. We reserve the right to deny a return or reduce the refund amount if the item is received in a condition that differs from what was originally shipped, including signs of use, missing parts, altered packaging, or damage that occurred after delivery.

    If a return is denied, the item will be shipped back to the customer at the customer's expense. We will attempt to contact the customer to arrange this. Denied returns left unclaimed after 30 days may be disposed of at our discretion.

    Fitment Responsibility

    Vehicle compatibility information is provided as a guide only and may not account for all modifications, trim levels, production changes, or custom applications.

    It is the customer's responsibility to verify fitment before ordering.

    Berry Performance Sales is not responsible for fitment issues resulting from vehicle modifications, engine swaps, aftermarket components, or inaccurate information provided at checkout.

    If you have questions regarding compatibility, please contact us before placing your order.

    Race Use & Off-Road Products

    Some products sold by Berry Performance Sales are intended for race use, off-road use, or closed-course competition only and may not be legal for use on public roads.

    It is the customer's responsibility to verify local, state, and federal regulations before installing or using these products on a street-driven vehicle.

    Berry Performance Sales is not responsible for fines, citations, emissions violations, or other legal consequences resulting from the use of race-only or off-road-only parts.

    Return Packaging Requirements

    Do not write on, tape directly to, or affix shipping labels to the manufacturer's packaging.

    Returned items must be shipped in an outer box or protective packaging sufficient to prevent damage during transit.

    Items returned with damaged, altered, or missing packaging may be subject to additional deductions or denial of the return.

    Customers are responsible for ensuring return packages are properly packed and delivered to us. We strongly recommend using a trackable and insured shipping service.

    Fees to Know Upfront

    We believe in being transparent about costs:

    • Restocking Fee: 20% — deducted from all approved return refunds
    • Return Shipping: Buyer's responsibility on all standard returns
    • Cancellation (Installment/Payment Plan): 7% fee to cover transaction costs
    • Cancellation (Credit Card/PayPal): 3.5% processing fee
    • Cancellation (Backordered Parts): 3.5% fee, regardless of payment method, to cover processing costs already incurred

    Damaged, Defective, or Incorrect Items

    If your order arrives damaged, defective, or incorrect, you must contact us within 48 hours of delivery at sales@berryperformancesales.com.

    Claims reported outside this window may not be eligible for resolution.

    When contacting us, please include:

    • Your order number
    • A description of the issue
    • Clear photos or video of the damage or defect

    Do not install, modify, or use a damaged, defective, or incorrect item. Installation or use of such items constitutes acceptance of the product's condition and may void eligibility for return, replacement, or warranty consideration.

    Items confirmed to be defective due to a manufacturing defect or fulfillment error will have return shipping costs covered by Berry Performance Sales.

    Manufacturer warranties are separate from our return policy and may require inspection, troubleshooting, or approval directly through the manufacturer.

    Refunds

    Once we receive and inspect your return, refunds are processed within 3–5 business days back to your original payment method.

    Original shipping charges, expedited shipping fees, freight charges, customs fees, duties, taxes, brokerage fees, and other non-refundable service costs are not eligible for reimbursement unless the return is the result of a verified fulfillment error by Berry Performance Sales.

    Refunds are issued only to the original payment method used at checkout.

    You'll receive a confirmation email once your refund has been issued.

    Payment Disputes

    If you experience an issue with your order, we ask that you contact us directly before initiating a chargeback or payment dispute.

    Most concerns can be resolved quickly through our customer support team.

    Questions?

    We're happy to help before, during, or after your purchase.

    Email: sales@berryperformancesales.com

    Berry Performance Sales reserves the right to update this policy at any time. Changes take effect immediately upon posting. It is the customer's responsibility to review the current policy at the time of purchase.

    Disclaimer

    All products are sold for off-road use only unless otherwise specified. Buyer assumes all responsibility for installation and operation. Seller is not liable for any incidental, indirect, or consequential damages — including engine failure, labor costs, or vehicle downtime — resulting from the use of any product sold.

    By making a purchase from Berry Performance Sales, you acknowledge and agree to abide by the terms and conditions of these Policies.

    For any questions or concerns, please contact us — we’re always happy to help.

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