p0036 and p0056 07 tahoe need help

[mike11747]

i have a 2007 tahoe with 110k i got a check engine light and check the codes and came up with p0036 and p0056 both for the o2 sensor bank 1 and 2 sensor 2 i changed both sensors cleared the code light came back on did some research online and was told to check the fuse went looked at the fuse was blown replaced the fuse car was fine for the whole day then next morning light came back on and the fuse was blown replaced it again cleared the light again and started the car but light came back with the blown fuse reading the codes p0036 and p0056


what should my next steps be and help or advice i would greatly apperecaite it thsnks in advance

 

[bladenbullet]

youre more than likely looking for an intermittent short in the circuit that supplies voltage to the o2 sensor heaters....the fuse supplies the circuit to the heaters and they are grounded through the ecm....trace the pink wire (ckt 539) looking for a chafe or possible burn on the exhaust somewhere...if the sensors are new you should be able to eliminate everything from them to the pcm as the heaters have enough resistance to prevent over current in the circuit....hope this helps....

 

[mike11747]

youre more than likely looking for an intermittent short in the circuit that supplies voltage to the o2 sensor heaters....the fuse supplies the circuit to the heaters and they are grounded through the ecm....trace the pink wire (ckt 539) looking for a chafe or possible burn on the exhaust somewhere...if the sensors are new you should be able to eliminate everything from them to the pcm as the heaters have enough resistance to prevent over current in the circuit....hope this helps....

thanks im going to look into this tonight