Another day, another issue

[Blackhawk_Mech]

So now I have check engine light on, and ODB-II says PO153. "Upstream heated O2 sensor circuit slow response. Bank 2"

Any idea? I thought it might be the o2 sensor on the cat, but that would be downstream.

 

[IZwack]

There are four O2 sensors -- pre cat and post cat. "Bank 2 upstream" is driver's side right before the cat.

 

[Blackhawk_Mech]

So saying the circuit is slow, could that mean the sensor is just dirty? Or will need to be replaced?

 

[BobWiersema]

So saying the circuit is slow, could that mean the sensor is just dirty? Or will need to be replaced?

No you can't clean them. And by the time you fight that thing out of the exhaust it will probably be destroyed anyway. Slow response means that the heater is weak or not working, that means that the o2 sensor is not going to work until the exhaust is up to operating temp. So the PCM can't adjust the fuel trim correctly and by the time it's hot enough from exhaust the system may be in Closed Loop Fault (Bad performance and mileage). If you have around 100K on the engine, go ahead and replace all the o2 sensors, they are about $50 each.

Bob