Ceck engine light B251-PO 155 NOW WHAT?

[tmils470]

so I got a check engine code read for me by AAMCO, they said it is and air fuel /o2 sensor on the rt bank.
Any suggestions on this code? Loose wire, bad sensor any other items to look for?
Is it common
Will it reset if the battery is dsconected? Shouls I worry about running too rich and damaging the cats?
Car runs fine (seat of pants)

 

[Trunk Monkey]

Usually replacing the sensor fixes it, but sometimes it can be something else up the chain. It will reset if you discon the battery, but it will come back and also won't fix the problem. You'd have to run it awhile to damage the cats.

 

[tmils470]

Which o2 sensor is it?
So you think I should just replace it and go from there.
I was considering the reset before I replace it to see if it was a fluk.
How much do they usually cost?

Thanks

 

[Dwight S]

There are two o2 sensors on each side. Total of 4. Each o2 sensor has it's own CEL code. The upstream sensor is different from the down stream sensor.You'll need to get the exact code to know which sensor it is.

Take it to AutoZone and let them check the code, they can tell you which sensor it is. Not too difficult to change out.

 

[Sandroad]

I think that code is bank 2, sensor 1. Denso O2 sensors are $70-$100 in auto parts stores. There is an excellent write up on diagnosis and replacement in the forum FAQs, including which photos of which banks have which sensors (there a total of 4).

 

[tmils470]

I will search for the write up.
I went to drive it to dinner tonight and there was now CEL.
I did not think they reset themselves.
Next time it comes up I will dig in deeper and just replace the faulty sensor.
Sure don't need this on a 1000 mile RT trip to Southern California.

Thank you for the help