It’s part of the evaporative emissions system (commonly referred to as “EVAP”) and reads pressure in the fuel system to detect evaporative leaks, such as a loose or faulty gas cap.

Inflate tires to the recommended tire pressure when cold, like in the morning after the car has been sitting. Check your car’s ... Step 2 Unscrew the cap on the valve stem.

Checking tire pressure and correcting it is a quick task that only requires two tools: a tire pressure gauge and an air compressor or tire inflator. Most gas ... car owner’s manual. Check ...