P0440 Chevrolet -

Question

there is no persure in my gas tank when i take gas cap off, I replaceed vent valve and purge cyn but I still have no presure in gas tank

Answer 1

Hi there,

There shouldn't be any pressure when you take off the gas cap. This code can mean a large variety of things, you really need to have the system tested to be sure there aren't any leaks in the system. A faulty pressure sensor can also cause this code to appear at any time.