We tested popular wideband O₂ controllers against lab-grade equipment to see how accurate their lambda readings really are under real engine conditions.

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 ...