Will I Get a Big Boost from Changing the ECU Chip? - Fuel Economy, Hypermiling, EcoModding News and Forum

Axaday · 06-29-2008, 05:08 PM

My work car, for the moment, is a 1989 Grand Prix and I just learned that it has a chip in it to determine the timing and stuff and there are replacement chips available on eBay. Am I really going to see a benefit from buying one of those?

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And for my 1997 Mustang, will the local Ford dealership be able to reprogram my ECU, or would I need to find a very special place?

SVOboy · 06-29-2008, 05:21 PM

Unless you're getting a custom tune, I really wouldn't expect much. Make sure anything you buy comes with a money back guarantee, as I've heard bad stuff about alot of these preprogrammed chips.

Axaday · 07-03-2008, 08:57 PM

I looked at the eBay feedback for a guy selling chips cheap and it turns out that they are just 3300 ohm resisters that you put in place of the IAT to tell your engine that the air is always cold. I don't want to bother with that.

What got me first looking at this was a guy at work telling me that my 89 Grand Prix came from the factory with a changeable chip to tell it how much gas to inject, what points to shift, and when to spark and that they set it up from the factory in the middle between what would give highest horse power and what would use the least gas and that by changing this chip I could turn it toward economy. But I'm not finding those for sale anywhere. Maybe just because it is a 20-year-old car?

He also said my 97 Mustang could be reprogrammed the same way through the OBD2 port, but the local Ford dealership won't participate. I don't know where to get this done and I'm really wondering if it is worth keeping on looking around.

garys_1k · 07-03-2008, 10:39 PM

The dealer can't do it because any recalibration like that would be illegal -- it'd trash the emissions certification they must adhere to.

As for recalibrating your car, the only thing likely to make a quick improvement is if you run with more spark advance, and that'd only be good if your fuel can handle it. Running more ethanol would help, but I don't know where you could get a recalibration kit to let you retune it.