Your oxygen (O2) sensors are small but mighty — they help your engine run efficiently, cut emissions, and prevent costly damage. With the right OBD-II scanner and a bit of know-how, you can decode ...

Q: I have a check-engine light that comes on after 50 miles or so and the fault code is 44 — that is bad oxygen sensor. I have changed both sensors, but the check engine light comes on with the same ...