GM Mechanics?

[ndbwhunter]

Any GM mechanics in here that could help me with code p0446 (evap vent valve)? When the code first appeared, I did some research and replaced the evap vent canister and solenoid, and re-routed the vent box with 5/8" heater hose to a location above the transmission. I cleared the code on Sunday, and the check engine light came back on today. I checked the code again, and it's the same thing. Do I have to blow out the line between the valve/solenoid and the charcoal canister? Or is it possible that the charcoal canister is bad?

 

[Stid2677]

A loose or faulty gas cap can trigger this as well.

 

[RdHawg]

You've got a vacuum leak more then likely. If you've got one available a smoke tester is your best friend. Blow it in - see where it leaks out.

Not sure if GM uses them but my wife jeep got a 446 when her vacuum test pump (I don't remember the exact name) went bad.

Could be a gas cap - more likely a hose that's either fallen of or rotted through. Recheck the routing of everything pay particular attention to the hoses right at mechanical connections that is usually where they rot thru.

 

[ndbwhunter]

I think the code for a leak is p0442 or 0449. The p0446 is a dust intrustion/clogged evap line/canister/solenoid code.

 

[RdHawg]

http://www.samarins.com/diagnose/p0446.html They say it makes a difference depending on the company maybe jeep just lumps it all together. Evap system leak is in the list of options though.