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 ...

One of the most important measurements we make while tuning an engine is finding out what the actual balance of air and fuel was inside the engine. It doesn’t matter if we have a carburetor, port ...

As the name suggests, oxygen sensors in a car’s exhaust system sniff for oxygen, the presence of which indicates incomplete combustion and unchecked pollution. This can trigger the check engine light.

Land Rover says some of its 2010-12 LR2 models may illuminate the Check Engine light and log O2 sensor trouble codes P2097 and P2099 in computer memory. If there are no drivability symptoms associated ...

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 ...