PO455?

[BlueCollarTahoe]

What you need is someone with a tech 2 or equivalent (not just a plain scan tool) to check the evap system. There is a guy (Eric) up in NY that owns his own shop and does alot of vids for even our C/K chassis GM's. Check this video out of his for knowledge of the Evap system and how to troubleshoot it.

Here is a video that goes into the P0455 code and a typical failure cause.

that vid looks good but its for an 07 no? the engine layout looks different in the vid. dont know anyone with one of those machines except the mechanic. i just got a basic scan tool thing. i was thinking about changing the 3 parts that were mentioned earlier ive seen those in some videos. i guess if those three dont fix it thrn ill have the shop take a look. just need some part numbers. worse comes to worse i guess im out some bucks but i did replace some factory pieces with new ones.

 

[igell]

so i have a similar issue.. where is the vapor canister located.. i changed the vent valve but didnt see a canister anywhere near by? 2001 denali

mine looks exactly like here:

 

[Rocket Man]

so i have a similar issue.. where is the vapor canister located.. i changed the vent valve but didnt see a canister anywhere near by? 2001 denali

mine looks exactly like here:

Vapor canister is right by the front of the gas tank.

 

[afpj]

https://www.tahoeyukonforum.com/threads/fueling-issues-what-i’ve-done.108566/

Lists part numbers and has vids (nearly the same)

 

[igell]

okay.. so i replaced both solenoids and the vapor canister.. yet i still get this code. I read on another threat that a fueltank sensor might cause this as well... is this my next option?

 

[Rocket Man]

okay.. so i replaced both solenoids and the vapor canister.. yet i still get this code. I read on another threat that a fueltank sensor might cause this as well... is this my next option?

Did you try a new GM gas cap? That’s usually the first thing to try.

 

[igell]

Did you try a new GM gas cap? That’s usually the first thing to try.

yup.. that was the first thing i did.
the only thing i did not do is blow out the lines..