Sensors

A penny sensor that can quietly ruin both starting and fuel consumption. It takes ten seconds and no tools to check — just compare two numbers in the

A code that can stall the engine on the move and refuse to start a minute later. Where to begin, and why the part is not first.

A mass air flow sensor lies gradually. The car still drives, just worse — and the numbers show it before you feel it.

The sensor rarely dies outright. Far more often it answers slowly — and live data shows it.

Sixty-seven parameters is a lot. Here are five that answer most questions about how the engine feels.