CEL P0171 / P0134 after getting A/C Expansion Valve replaced. Well maintained and no other issues before AC repair. Please advise what to check. Prefer not to take back to mechanic.
Current miles 157704.
Code p0134 is bad oxygen sensor bank #1 code p0170 is bad oxygen sensor not heating up.
Thank you Bender. I did look up the code but I feel like it is too much of a coincidence for it to occur after taking it in and I do not want to bring it back to the same mechanic. Are there any test I can DIY to determine if the sensor is bad?