o2 sensor errors after exhaust change

[.adam.]

Just had my exhaust changed, a cat back system, and the car has now thrown 2 errors, a P0036 and a P0056 (Sensor 2 on both banks). I'm wondering if during the exhaust change, with all the drilling and grinding to get the old bolts off, if the vibrations may have damaged both sensors? I've tried clearing the codes, which works until I need to restart the engine.

[j3nks79]

More than likely. The are very sensitive. Even touching the tips with your hands when fitting them can mess them up.
Or other option is if you didn’t use new gaskets air it getting in and affecting the readings

[.adam.]

New gaskets from BMW were used, so sounds like it's new sensor time!

[.adam.]

Going to order a couple as I can send them back at no cost if I don't use them, are these the correct ones, does anyone know?

https://www.autodoc.co.uk/bosch/1149533
https://www.autodoc.co.uk/bosch/1149284

They list 4 Bosch post cat sensors, but these two are half the price of the others.

[Mike6]

I have that problem in reverse after new post cat 02 sensors were changed. Took car back to garage and they checked and said sensors were all tight and no problem with exhaust joint. Suggested air was getting in on inlet side so I stripped everything down and no cracks or splits. Probably need a smoke test to eliminate completely but I am still convinced it was something garage did which is now throwing codes on both banks for fuel preparation. Going round in circles now