Q: In my vehicle, the check engine light comes on and then goes off and it is now back on. I had a test done at local auto-parts store that showed a code of PO138. They told me this indicates a ...

Last month, we kicked this series off by showing you how to save some money by diagnosing a bad MAP sensor rather than just chucking cash at new parts that may or may not fix a specific problem. This ...

I had a test done at local auto-parts store that showed a code of PO138. They told me this indicates a problem with the oxygen sensor. I replaced the oxygen sensor and the light never went out. I ...