Last month, we kicked this series off by showing you how to save some money by diagnosing a bad MAP sensor rather than just chucking cash at new parts that may or may not fix a specific problem. This ...

In the world of automotive tuning, knowledge is horsepower. Gauges, loggers, and sensors galore provide the data to advance performance, solve problems, and prevent expensive engines from experiencing ...

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 store that showed a code of PO138. They told me this indicates a ...

A closed loop control system for regulation of engine air-fuel ratio at the stoichiometric value is required for effective operation of a three-way catalytic converter. System performance depends ...

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 ...