engine code p440 will not turn off on 2002 GMC Envoy

engine light on , fogged from both ends, charcoal cannister replaced celenoids cleaned and still p440

by in Ojibwa, WI on October 12, 2013
1 answer
ANSWER by on October 12, 2013
Run evap test; Check for change in fuel tank pressure sensor. If no change and no leaks, possible bad sensor in fuel pump module.