SHO_GuN

It is: 02 Sensor Circuit Malfunction (Bank 2 Sensor 2). I replaced the sensor with an NTK brand. I don't know if the code would have stayed gone because of the following.

Right after replacing said sensor, my intake gasket started leaking. Turned out to be the intake had a corner broken off so had to replace it too. The head gasket blew the next day. It was leaking antifreeze into 3 & 4.

So I now have replaced my head gasket and intake and the P0156 is back. Have reset it several times but keeps returning. I have visually inspected the wires to the sensor as best I could and saw no problem. Granted it has been doused with antifreeze, but so have the 3 older sensors and they aren't coding.

Does anyone know what the diagnosis procedure is for this code? I thought the dealer's machine gave them real time data to pinpoint the problem, but they told me they would just read the code then "go to the books" taking ohm readings and whatnot.

TIA

Turbo X_J

Code points to a problem with the circuit, not always a sensor the wiring is all fine? Are you sure the clyinder head is not toast?

SHO_GuN

I guess not all 0331 heads are bad. It was very obvious looking at the head gasket where it had failed letting coolant go into cylinders 3 & 4. There was no indication of the infamous crack/leak in the head itself between cyl 3 & 4 nor was there any indication of coolant in the oil. The engine has 158k on it and doesn't sound all that good to start with so I just cleaned the head up, checked it with a straight edge and slapped it back on. I would put a reman engine in it before I spent $500 on a new head. So far not an ounce of coolant has gone missing.