P0451 - 2012 Mazda 5

Question

This code comes up (P0451, Evaporative Emission System Pressure Sensor/Switch), smells like gas occasionally...thought it was the fuel cap and had the code cleared by Advanced Auto but it came back on two days later.

Answer 1

HI there,

The code usually pops up when there is an issue with the vent control valve. The pressure sensor itself isn't the problem or what causes the fuel smell. The pressure sensor knows or thinks it's not working properly because no pressure is building up. This is usually a result of a bad vent control valve.