Painless Performance EFI Harness

Say Goodbye to Junkyard Wires

Swapping in a late-model EFI motor into your muscle car can be a complicated task. The most difficult task is finding a compatible EFI wiring harness and connecting everything to rest of your vehicle.

painless efi wiring harness

Using the Junkyard Factory Wires is Frustrating

You might save some money trying to splice old wires and going through old factory wiring diagrams. But be ready to spend a lot of time and probably more than a few swear words. You’ll soon learn a few hundred dollars in a new Painless EFI wiring harness is a great investment in both your sanity and engine swap project.

avoid messy factory wiring


What Makes a Painless Harness Foolproof?

After reading dozens of reviews and watching several videos, there are four key reasons to consider a Painless Performance EFI Harness for your engine swap:

(1) Application Specific: Painless has taken the guesswork out of what connectors and wires you need. Simply locate the OE motor from which your EFI system was taken from and locate the appropriate Painless kit. See their site HERE to get started.

(2) Fully Tested: Each Painless EFI Harness is fully tested before it leaves the factory in Fort Worth, Texas. If you’ve spent hours trying to locate a bad connection, you’ll certainly appreciate this. This video details the company’s testing process:

(3) OE Factory Components: Every wire, connector and hardware is factory-new and OE-level quality.

(4) Comprehensive Instructions: Each kit includes a multi-page instruction manual with great pictures and diagrams. And if you need help, just give the Tech Line in Texas a call. Click HERE for a sample instruction manual.
Sample of a diagram from the user manual:
painless peroformance efi harness instructions


Watch Product Summary Video


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Painless Performance





(817) 244-6212


2501 Ludelle St

Fort Worth, Texas 76105

ABOUT Painless Performance®

In 2017 we celebrate 27 years in business – 27 years of helping our fellow rodders, our friends in racing and off-roading, find painless solutions to their automotive electrical needs. What started out as a single idea about a simplified way to wire a street rod has evolved into what is today a multi-faceted company with sixty-six employees in a modern 45,000 square foot facility manufacturing over 500 products for show cars, dragsters, rock crawlers and everything in between.