As you may see I am new to the forum. Wednesday night I puchased a 2000 GTP with 16300 mi. I couldn't resist the price! There really wasn't a ton wrong with it, but I began having it worked on IMMEDIATELY!!!. I had to replace the intake and supercharger gasket, belts, fluids, plugs, and thermostat. RAN LIKE GREASED LIGHTING!!! I knew that it had an exhaust leak, but it was a bad donut at the flange where the converter and the resonator meet. I took the car to the guy that normally does all of my exhaust and suspension work (needed new front struts and springs) and I let him talk me into replacing the exhaust from the downpipe back.
Every thing is replaced w/what I believe is 2.5 inch exhaust ( I didn't measure it), but now my car runs like crap!!!! It sputters, hesitates, fuel mileage sucks and it has cut out on me! The problems showed up IMMEDIATELY. There is no guessing that the change in exhaust caused the issue.
NOW:
There is no bend coming out of the convertor into the resonator as before, so there is less back pressure, could that be an issue,
OR:
Is it possible that something needs to be recalibrated to make up for the change in exhaust,
OR:
Is it it possible that I have been dupped and have cheap or undersized components (Convertor) on my car, (my vote)
OR:
Possible O2 sensor problem when the convertor was installed?