P0171 Chevrolet -

Question

Replaced O2sensor front driver side and engine light came on. X

Answer 1

Hi there,

This code can also be caused by an intake air leak on bank 1, a faulty converter can puh exhaust back up into the cylinders and cause it, leaking exhaust can be another reason to get the lean code like this. You can check for vacuum leaks by spraying some carb cleaner along the intake with the engine running.