OK, this is what im going through. I am working on fixing my mothers car and bringing it back to a joyful ride.

So far, replaced broken clutch pedal, shortly after it started missing and 2 coils got replaced, so far so good...(i guess) --- then I got the check engine light and it gave me codes for pre catalytic converters under efficiency. I replaced this for highflow cats made by racing line. I cleared the codes and have since gotten the cat under efficiency codes again, twice. At one point i had gotten a bank 1 sensor 1 code but after clearing it and changing cats it never came back. So im thinking i have to replace o2 sensors to make this "cat under efficiency" code go away. It is catalytic bank 1 p0420.

This led to me realizing some o2 sensors are specified for automatic transmission. I could not find the part number for sensor 1 bank 1 manual transmission. Does anyone have this?

http://www.racinglineperformance.com...p?idproduct=64