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 ...

One of the most important measurements we make while tuning an engine is finding out what the actual balance of air and fuel was inside the engine. It doesn’t matter if we have a carburetor, port ...

We earn commissions from purchases you make using links in our articles. Learn more. If your car experiences poor fuel economy, lacks power, feels sluggish, idles rough, or has an illuminated check ...