heres the situtation....i recently installed a 3 inch downpipe and replaced my cat with a test pipe with a qtp electric cutout welded in the test pipe...also on the install i installed a mechanical CEL fix for the rear 02 sensor when i first installed all this i reset the ecu by touching the positive and negative cables...and for about 2 - 3 weeks no CEL...but then a week ago i noticed my clutch slipping so i went and tested it and floored it and when my rpm jumped the CEL came on? i went to autozone and they told me it was a P0136 Oxygen Sensor Circuit Malfunction (Bank 1 Sensor 2) and P0139 Oxygen Sensor Circuit Slow Response (Bank 1 Sensor 2)... So this was on for a couple days then one day i checked my oil and clutch fluid resivoir and few other things just checkin out my engine and what not then later when i left it was off? then later that night i got in my car to go home and it was on again?! i dunno whats does this but i downloaded Scan tech and deleted the codes to see if they will come back on and they havent yet....if you guys have any idea what it could be let me know

 

Sounds like your O2 sensor is starting to go.

 

one thing after another....gotta replace the clutch...and now my brakes are squeekin at me now a o2 sensor...damn!! haha