Try the engine coolant temperature sensor. I was getting the p0157 code for bank 2 only.. 2004 hummer h2

it would come on after heating up replacets the 2 oxygen sensors, the 2 catalytic cconverters and the pipes from the manifold.

So the shop checked the fuel pressure, ok. Appeared no shorted wires, & did not check. I switched the sensors, copper brushed them cleaner too. Then on to the engine coolant temperature sensor. Got ac delco part 12608814, it is below the first plug on the driver side. That was it , no more fn codes. Did not have to change the harness or update the pcm/ecm.

Its the engine coolant temperature sensor for me. Good luck $47 at dealer $19 online?


P0157 code on h2 2004 fixed for me

try the engine coolant temperature sensor. I was getting the p0157 code for bank 2 only.. 2004 hummer h2

it would come on after heating up, i replaced the 2 oxygen sensors, the 2 catalytic cconverters and the pipes from the manifold.

So the shop checked the fuel pressure, ok. There appeared to be no shorted wires, & i did not check with a meter. . I switched the sensors, copper brushed them cleaner too. No go. Then on to the engine coolant temperature sensor. Got ac delco part 12608814, it is located below the first plug on the driver side. I put new one on. Let enging cool down, squirts out about a water bottle of fluid out

. I also read that prestone was the one to use that mixed with all the other brands of anti freeze. That was it , no more fn codes. I did not have to change the harness or update the pcm/ecm.

Its the engine coolant temperature sensor for me. Good luck $47 at dealer $19 online? Gm part 12608814

 

Same here. My 2005 H2 started running bad and didnt shift right. Trans temp was normal but engine temp was low. Changed coolent sensor and cleared the codes. Runs great. 25.00 from Atuozone. Didnt drain coolent, just did quick change and obly lost an once or two.