Hi,
This car doesn't have much power, it feels like it's being held back and sometimes when it's cold and you hit the gas it stumbles. I know those can both be caused by a clogged cat, especially since I have a code P0420 even after replacing both o2 sensors. I'm assuming it's the cat underneath the car, not the precat? Can anyone confirm this, that the P0420 indicated it's the main cat not the pre-cat? Also I have been looking on Ebay for an aftermarket cat bc I can't afford a new one. Has anyone used a specific aftermarket one and had good luck with it not throwing a code from being a little different? I know the oem cat has the o2 sensor in the middle of the cat, most of the aftermarket ones hold the o2 sensor afterwards. I didn't know if that would matter or not.

thanks,
Mike

 

I guess it depends on your location. I found a federal compliant MagnaFlow on amazon for less than $200 and it has the center mounted O2 sensor so that the wire and clips remain the same. Of course that needs to be welded in place, but still cheaper than paying the dealer $1300 for the whole pipe and cat together.