P0440 Pontiac - Sunfire-2003

Question

Car has PO440. Definitely not the gas cap. Have tried 3 caps. The one on now is an orginal cap from a 2004 that I also own. Still showing 440 code.

Answer 1

Hi there,

A lot of the time a bad vent control valve can cause this code as well. If the gas cap isn't resolving the issue then you really need to do a smoke test to find out where the leak on the system is.