Holley EFI Hp Ecu And Harness Ls1 & Ls6

Just writing this to offset the 1 star of the other reviewer. To say that this is very badly made is to be dishonest, likely due to frustration with getting a car running (something I can relate to all too well), and that is unfair. After having initially bought a standalone from another vendor that was good-but-not-great I was frankly surprised at how well this harness was made. I do wish some of the wires were about 2-3 inches longer, but that is more a result of my routing choices and less a fault of the system (I'm going to add an extension or two later). The wires are of good quality, the loom is nice and all the ends are well-wrapped and secure. It even comes with an O2 sensor.Install was fairly easy and I had my old harness out and this one in in a few hours. Setup was a bit confusing at first but I have zero experience with tuning, though once I took it upon myself to learn a bit about how fuel systems actually work and what the various terminology meant it wasn't that hard to get at least semi-proficient. But again, that is to be expected; if you don't know what you're doing then no tool will be of any help to you.So, some pros - It's pretty universal, some adapters might be needed here or there during an engine swap but that's not a surprise. It's not much more expensive than a good PSI harness + a tune. It doesn't require fees or licenses to use like some products do. It's easy to plug in a laptop and play around with it, plus you get to keep the various profiles yourself. Holley forums and tech support are also pretty good about helping you.Some cons - It's not cheap. Some of the wires could be a bit longer. The labeling of the wires is nice, but not very permanent. I wish the power wire were a few feet longer. I wish the midline fuses were either closer to or farther away from the computer, as it is they are in an awkward place [for my setup (71 Chevelle with computer above glove box and harness going through vent, the fuses are down in the vent)], but I'm planning to move it and go through firewall so this could change.Overall though, this product, like most Holley products (except their early LS swap headers, which aren't ideal) is a solid choice assuming you can spare the $$$. Their AC bracket for LS motors is also top-notch and worlds better than any of the hundreds of 2-sheets-of-steel-connected-by-spacers designs floating around.

This is the worst wiring harness I avtrust regrst. spending my money on this bad harness . First no power going to injectors and Sparks wirs going to the rely is mixed up. Now can't start the engine i don't now why. can't trust the product.This engine was running with my previous harness and ECU setup on the same car!!!