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 ...

Let's begin with the basics here: An automotive oxygen sensor is part of the exhaust system and does what its name implies, sensing how much oxygen is in the exhaust gases. And that's important for at ...

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, ...