Diablosport Forums

I just bought a 2005 GTO from a dealer in Colorado. I got a good deal on it and although this car is fast, it does'nt seem 400 Hp fast. The salesman said it was chipped and it has decals under the hood with claims of 440 Hp. It idles kinda choppy and when cruising with the engine loafing, 900 - 1100 RPM I can hear what sounds like slop in the valve train. My question is how can I tell if it has an aftermarket chip(if there is such a thing for LS-2) and can I just buy the Predator programmer, return to stock settings and see how it runs and tune from there? I beleive the problem is with the programming of my computer and would like to return to factory settings with the option to tune up or down easily. Any help or contact info would be great.

Your best bet would to ask the dealer if they could flash it back to stock for you using their factory tools. The predator will take a backup of whatever is in your pcm, tune or no tune and then apply our tune on top of that, so that would probably not fix your issue. Sounds like you might have a cam in the vehicle.

Thanks for the advice, I'll have the dealer re-flash it. What are the projected gains with the Predator for the LS-2 engine? I can't find any charts or verbage on horsepower gains. Also if the vehicle has a larger cam will the factory tune make my car run even worse?
Thanks much, Brad

The Predator will pick up about 20rwhp on a 6 speed GTO.
The cam will cause some issues with the stock tune, but it will depend how big it is as to how much of a problem it will cause.

Thanks

Thanks bro, I will re-flash on 5-9, until then it will not be driven. I don't think my car has a aftermarket cam in it, if it does it certainly does'nt perform like it. If all goes well then I will be a customer soon. If not, ANY advice or people I can get in touch with would be a great help. I just want to go really fast. Thanks again. Keep up the good work.
Brad

Check out LS2GTO.com for a group of GTO junkies like yourself.

Thanks