P0455 Code Help!

[tawd77]

Hello, I keep getting a code P0455 in my 03 Yukon Denali 6.0 - If I clear the code, it usually come back if I floor the throttle while driving. I have checked the gas cap and its tight. Any other ideas to what could be wrong? Thanks!

[D&SYukonDenali]

Here is the description of the code:

 

"Evaporative Emission Control System Leak Detected (Gross Leak)"

 

I would pop the hood with the engine running and look for any cracked hoses and listen wistling noises. Any recent mods?

[tawd77]

Here is the description of the code:

 

"Evaporative Emission Control System Leak Detected (Gross Leak)"

 

I would pop the hood with the engine running and look for any cracked hoses and listen wistling noises. Any recent mods?

 

no, no mods. I will listen for a vacuum leak... anything else?

[D&SYukonDenali]

I would guess something with the air pump or lines connected to it (just a guess).

 

I'd go to a place like AutoZone, tell them the code, they'll punch it up and give a couple reasons for the code (free of charge).