What is code p0496 for the chevy avalanche?

Diagnostic trouble code (DTC) P0496 indicates "EVAP Flow During a Non-Purge Condition", which means that if You live in a state that requires emissions inspections, You've got a problem on Your hands. Well, You do either way -- it's just more urgent! In other words, the code means that You've got a problem with the purge flow within Your EVAP system. There are a number of different causes, and the fixes are just as numerous. You should begin Your diagnosis at the EVAP purge volume control valve, since this is the most common. If this isn't Your issue, You can move onto the EVAP pressure sensor, EVAP system hoses, electrical connectors, and charcoal canister. It's exceedingly likely that before the end of the list, You'll find Your issue.