Chappy1062

I knew there would be a learning curve and that it's always a gamble when you buy used. In the three weeks that I've owned this 08 coupe with 33K miles, I've over come a clearance problem with the exhaust and the constant bumping in tunnel after it heated up (thanks Top Gun in FWB). I was not provided any information from the previous owner so I learned that it has PFADT headers, high flow cats, X-pipes, dual mode exhaust with Mild to Wild installed, and Halltech cold air induction system. I'm not sure if the Halltech is a 103 or 108 but it has the 4.5" inch filter. No other distinguishing markings tube that I could find. Three days after purchase it set Engine codes PO455 evaporative emissions system leak detected gross leak / no. Changed the gas cap for this. It also set PO420 catalyst system efficiency below threshold bank one confirmed (cats looks good) and nothing was set on the right side. With all the mods this car has, I have to believe that it has a tune but I'm not sure. My question is should I look into having someone read the current tune, get a "new tune", or are there any other maintenance area(s) I should be looking into? Recommendation/Advice?

jim2092

Those headers and cats usually require a tune change. Have a competent tuner check your tune and make the necessary adjustments. Those adjustments may eliminate your issues.

Chappy1062

Thanks... Now to find that "competent" tuner locally here in North Florida. Or the other options is to look at the available tuners on the market and work long distance for a custom tune. Reading through the forums there seems to be several with their loyal following..

tblu92

The front 02's are the most important---they control the AFR of your engine during all P/T driving trying to always achieve a fuel ratio of 14.68
The rear 02's are there ONLY to report the condition of your cats---Typically LT headrs and hi flow cats will produce rear 02 codes and cat efficiency codes---If you bought your car with these mods the previous owners tuner should have deleted all the rear 02 codes and cat efficientcy codes----If you don't have a local tuner any mail order tuner can fix all those false codes permanently so they won't re-appear
Same for the Evap codes---Any car about 6-8 years old starts showing evap codes This is normal---Again a tuner can permanently delete them--- mail order tunes run about $150 really all you need if you haven't installed any more performance parts

Chappy1062

Thanks, I'm readding all I can on custom tunes and the individuals that write them. Just with-in this fourm there seems to be loyal followings. I'm trying not to over research this, but I want to make the right choice. If I have problems I want to know I will get a response in a reasonable amount of time....... Thanks again for taking the time to reply. Regards

jim2092

A little confusion here.

First the front O2 sensors measure the existence of oxygen. Whether they attempt to maintain 14.68 afr would depend on several things including what type of gas you were using.

Second a mail order tune "is not all you need". A mail order tune would require the use of hardware/software to install which you would have to buy, borrow, or pay someone to use to load the tune into your car.

Chappy1062

Thanks! I should have been clearer on my reply. I knew I would need that hardware as well. I think I've decided on purchasing one of the Diablo tuners and a custom tune...