Error Code Help P0455 Evaporative Emission Control System Leak

[adrianb]

Hey gang -
I have a 2003 Tahoe LT 4x4 with 52k. Last weekend I got a check engine light. I checked it on Saturday, got the code and cleared it to see if it was just a fluke. The code was P0455 which is defined as "Evaporative Emission Control System Leak Detected (gross leak)"

The light came back on today so I know I definitely have a problem. I did a couple searches here and found this thread http://www.tahoeforum.com/showthread.php?t=9286
which suggests an obstruction in a vent line.

Unfortunately the original poster didn't reply with any results so I'm not sure if that is worth tracking down. I've got a great mechanic who can help me with this but if it is something simple, I'd like to try it myself.

Thanks in advance for your help.

AB

EDIT - it looks as though my post would be more appropriate in the "Technical Discussions" forum...I can't seem to figure out how to move it. If a mod/admin can make that happen, I'd appreciate it. Sorry for the foul up.

 

[RIDE N FLY]

I have the same problem that just occued two days ago. i took it to autozone and had it chkd and the diagnostic said it was a large leak in the evap system. possible causes
1.defective, loose or missing fuel cap
2. evap canister broke, hose cracked or not connected
3. purge or vent solenoid defective
4. vacuum leak at engine

well i changed the solenoid and the evap canister under the vehicle about a month ago. still having the same problem any help would greatly be appreciated.

 

[jey_]

Have you tried a different fuel cap?

 

[adrianb]

Yep - I tried retightening the filler cap on Wednesday and have been error code free so far. <fingers crossed>