This caused two additional codes to store in the system along with the O2 sensor code. Ultimately, loosening and retightening the two ground strap bolts allowed us to clear all the codes from memory.

Answer: Kristopher, as you know, lean oxygen sensor and fuel trim codes can be some of the hardest fault codes to diagnose.

Dura Lube users report success in clearing O2 sensor codes. Photo credit: Amazon.com. Liqui Moly Catalytic-System Cleaner must be sprayed in through the throttle body. Photo credit: Amazon.com.

Mike, this is not an uncommon problem, fault code 36 is for the burn-off function of the mass airflow sensor.

What would throw a code is an improper air mixture in the exhaust, as measured by the oxygen sensor (s). A plugged cat could cause this but wouldn't necessarily. Your symptoms could also be ...

The P0171 "System Too Lean, Bank One" fault code you experienced is only one of the many fault codes a MAF sensor can set when under- or over-reporting the amount of air flowing into the engine.

The oxygen sensor was replaced but the 'check engine' light won't go out. Now what? Which octane fuel is best? AAA's Car Doctor has answers.