Why it matters: O2 sensors feed critical data to your ECU, helping maintain the ideal air-fuel ratio for performance, efficiency, and emissions control. Reading the signals: Healthy upstream sensors ...

What are lean codes: P0171 and P0174 indicate a lean fuel mixture on Bank 1 and Bank 2, often detected by upstream oxygen sensors. Why they matter: Lean conditions can cause misfires, hesitation, ...

Q:Hi James. I keep having an oxygen sensor fault code for a lean exhaust with my '97 Corvette. I've taken the vehicle to the dealer several times but the problem keeps recurring. I would like to try ...