2000 Silverado P0155 Code

[KDML]

My SES light turned on so I went to the local auto store and borrowed their code scanner. It showed P0155 O2 sensor heater circuit malfunction (bank 2 sensor 1). I assume this means I need to change the O2 sensor as they are original at about 92,000 miles.

There are 4 sensors - which would be bank 2 sensor 1? Is there any rule that says I should replace them all or replace both upper or lowers at the same time? I would much rather only replace the one defective sensor.

Thanks
Doug

[j cAT]

Originally Posted by KDML

My SES light turned on so I went to the local auto store and borrowed their code scanner. It showed P0155 O2 sensor heater circuit malfunction (bank 2 sensor 1). I assume this means I need to change the O2 sensor as they are original at about 92,000 miles.

There are 4 sensors - which would be bank 2 sensor 1? Is there any rule that says I should replace them all or replace both upper or lowers at the same time? I would much rather only replace the one defective sensor.

Thanks
Doug

the bank 2 sensor 1 is the upstream passenger side sensor..this could be a bad heater in the sensor or the sensor wiring is defective/not correctly run and has resulted in wire/connector failure.

check for any fuses blown ...

[KDML]

Thanks

I will look at the fuses and wiring before replacing the sensor. Are there fuses specific to the sensor or could any fuse do this?

I cleared the codes with the scanner, but the SES light came back on about 45 mins later

[j cAT]

Originally Posted by KDML

Thanks

I will look at the fuses and wiring before replacing the sensor. Are there fuses specific to the sensor or could any fuse do this?

I cleared the codes with the scanner, but the SES light came back on about 45 mins later

since it took 45min to come back I would think wiring / connector / or sensor...if it is the sensor replace both upstream sensors ..when checking sensors make sure you get the same connector on the replacement sensors..