I had a p0304 code and after replacing plugs, coils and wires, it was determined that there was an issue with the piston...I honestly don't know what the mechanic did bc he had a strong Spanish accent but he replaced all the gaskets. At that time I only 1 code...I still have a check engine light and it now reads p0420. Most mechanics I speak to without even looking at the vehicle say it's the cat converter. I've already prepared myself to get that fixed I just need some advice. 1 shops says he can do a magnaflow converter (which he says has to be California accepted bc my car is supercharged) for 225$. Another guy says he can do a direct fit converter for 550$. Now keep in mind no one is doing anything until it is confirmed that the cat is bad...but should I do the universal Magnaflow or direct fit?
04 GP gtp
