Where is the fuel tank pressure sensor on a 1999 Chevy Express van?

On a 1999 Chevy Express van, the fuel tank pressure sensor is located on the top of the fuel tank, typically integrated with the fuel pump assembly. To access it, you may need to remove the fuel tank or at least lower it, as the sensor is not easily accessible from underneath the vehicle. Make sure to relieve the fuel system pressure before attempting any repairs.