Add Yahoo as a preferred source to see more of our stories on Google. 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 ...

Your car's O2 sensor can cause rough running, bad mileage, and inspection nightmares. Can a quick clean save the day? Here's what you need to know.

While relatively minor, check engine light repairs can be costly if neglected, leading to as much as 40 percent lower fuel efficiency. Metro News Service photo While relatively minor, check engine ...

The "Check Engine" light is the most feared dashboard notification, but for the Oxygen (O2) sensor, it is a lagging indicator. By the time that light illuminates to tell you your O2 sensor has failed, ...

Don't let failing oxygen sensors compromise your engine's performance. O2 sensors are critical to emissions control on your car, SUV or truck. As the name implies, the O2 sensor (also called an ...

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 ...