My CEL is on and I have the following codes: P0141 P0161 P0160 which are both downstream O2 heater circuits and the bank 2 O2 sensor. Is there a good way to make sure it's the O2 sensors that need to be replaced rather than a wiring/ECM issue? I've checked the 15 amp F2 and it's intact.

 

Now I appear to be down to just the 141 and 161. I'm going to check the heater circuit today. Should it be 12V when the car is turned on?

 

I had a similar issue with my Walker "economy" downstream sensor. Replaced it with Walker OE sensor and issue resolved.

 

Thanks for the reply. I've got two new NTK sensors but I was hoping to check the circuit before I drop them in since they were like $75 a piece. Were you getting the same code?

 

I think the circuit is good. getting 12 volts on the brown wire and the ECM seems to be pulsing the white wire to ground when the car is started. Still getting the 141 and 161 codes with a new NTK sensor (only changed one). When you guys get bad sensors out of the box, is it the sensor or the heater or either one that doesn't work? Could I have received a sensor that has a bad heating element?

 

Spunds like an ECU or ground issue but others may know better than me. BTW, I PM'd you the info you wanted. Let us know how you make out with the error codes.

 

I switched both rear sensors and no more CEL. Thought I would post the resolution for posterity's sake.

 

which brand did you use for the rear sensors?

 

I went with NTK, someone in another thread recommended them. Kind of expensive, but I passed emissions!

 

That's good to know. thank you for the update and glad that you worked out your O2 sensor issue.