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 ...

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 ...

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 ...