This might be a retarded question but how many other O2 sensors do our cars have besides the 2 located by the cats? Broad question but what might cause the sensors to go bad. If there is an exhaust leak AFTER the sensor would it cause the code as well?

current setup: MREV2, 5/16 plenum spacer, APS tall boy, stillen intake, STOCK headers, BERK HFC, JIC y pipe, STOCK midpipe, gReddy Elite muffler.

 

4 O2 sensors, 2 on exhaust manifold, 2 on cats

yes, it will throw a code even if the leak is after the sensor. An exhaust leak doesn't just bleed exhaust out but will also suck in ambient air

Check your HFC for cracks, then check for leaks around the cat (exhaust manifold side and y pipe side)

 

I will check that tmrw, hopefully there aren't any cracks on my HFCs. I didn't have this much problems with megan's RTPs w/ there 2in flex coupling but can't stand the rasp. I know it's from the stress of the motor which cause my exhaust leak (JIC y-pipe meets stock mid-pipe) which could possibly cause my SES light to come on. i will take a look at that bank 2 sensor 1 now that i know it's located in the headers. Thank you for clearing that up!