NEWB.... Help With Emission System
 

Hello all,

I am new to the forum, so I just wanted to say Hello first...

Anyway, I have a 2003 Silverado with a 4.8 Auto, and I have an error code of P0455, which is Evap/emission Large leak. Normally this is just a loose or cracked gas cap, I know that much... It also could be a vacuum leak somewhere, or something to do with your charcoal canister/solenoid/valve not operating properly. I have checked over all the hoses, and the gas cap is on tight. I have a feeling that the valve is stuck open because there is A-LOT of pressure in the fuel tank when the tank is low when I remove the gas cap after driving for a while. Before I bring this thing in to the stealer and sign my life away, I want to know if anyone has had this problem, and what they did to fix it?!?!? I am not a mechanic, but have all the tools, and am pretty mechanically inclined... Please let me know if there is anything that can help besides bringing it to the stealership.

Thanks,
Matt