'05 GP emissions code P0455

[supreme_style21]

My brother just bought an '05 Grand Prix gt2. It's throwing an emissions code P0455

It's the 3.8 with 78k on it.

He's replaced the gas cap with one straight from the dealership, twice. That's all he's done. It's still throwing the code. If the code is cleared, it just takes a short trip to throw the SES light again. What could be some things to check?

[BXX]

Get a vent solenoid, should be around $25. slap it on, clear the code and all should be well. While your at the vent solenoid, check the wire connection for damage or corrosion and for a possible deteriorated hose back there,

 

But the vent solenoids are sooooo very common on the GMs to fail and they throw a P0455. Already had to do one on my 06 Impy

[supreme_style21]

That's exactly what it was! Changed it and all is well now

thanks !

[BXX]

Sweet! Glad you got it fixed!