Ok guys I have been having some issues with my car bogging down while idling. My service engine light has been on for a while because of a bad cat, but i don't have to do emissions and I didn't notice a drop in mpg so i haven't fixed it. But since my car started bogging down while idling i figured it would be a good idea to rescan my car. I now have 3 different codes. I have a cylinder 4 misfire, P0135(O2S heater ckt malfunction 1/1), and P0420 (Catalytic converter efficiency below threshold (bank1)). I figured its probably just my cat, so I bought a new one but haven't installed it yet. Is there anything else I should get, like a new upstream 02 sensor, or is there something else I should try before I install my cat?
Originally Posted by Bio248
