I have a 2007 Silverado Classic. Original owner, 167k miles with the 5.3L Flex V8.

I've had a constant P0442 error (Engine light on) that I can't seem to get resolved.

A couple years ago the problem started. I replaced the Vapor Cannister Vent Valve (near the fuel tank) and the gas cap.

I cleared the code and this worked for about a year, when the code came back. I again replaced the Vapor Cannister Vent Valve and added the Vapor Cannister Vent Valve (on the front of the intake manifold).
I cleared the code again and it stayed clear for about a week, with about 200 miles driving.

Yesterday, I started the truck and the code came back. I've examined the schrader valve at the front of the Vapor Cannister Vent Valve on the engine. I removed it, verified the seal and re-installed.

All the hoses appear good visually.

Any help would be appreciated.

RickR90s

 

Rick here is some help:

With a P0442, the most common DIY repair is to:
Remove and reinstall the gas cap, clear the codes, and drive for a day and see if the codes come back.
Otherwise, replace the gas cap.
Visually inspect the EVAP system for cuts/holes in tubes/hoses

More advanced troubleshooting steps include: Using an advanced scan tool, perform an EVAP leak test
Verify operation of the EVAP purge solenoid / valve Perform a smoke test to see where the leak is.

 

thanks very much. I have checked the gas cap area for corrosion (there isn’t any). I have an appt with my mechanic to use his smoke machine.