Here is the situation. This is the third o2 sensor sim that I have installed about 3 months ago and it only worked for about 10 minutes. The previous identicle one lasted about 6 months. Anyways, the engine light was for about 3 months now and a couple of days ago, the engine light went off without me resetting it. I put my OBD2 reader on it and it gave me 2 codes. The first one is a P0420 which is the one that always came on before. The second code is P0138 which is "Secondary Heated Oxigen Sensor Circuit High Voltage" error. Why would my engine light go off after it was on for 3 months and with 2 engine faults, shouldn't it stay on?

I would like to know how I can fix this problem too. Another sim maybe??

Any help would be greatly appreciated

Thank you

Andre