P0455 Code On 2006 Silverado Crew Cab

[06ado]

I've seen a variety of posts on the evap codes but before I buy parts I just wanted to be sure.

 

I have a 2006 Silverado Crew Cab LT3 with 5.3L. Vehicle has 38,000 miles. No trouble till recently when DIC showed "tighten fuel cap" message intermittently and CEL is now on. Went to 2 AutoZones and asked them to check code. It shows only P0455 atboth Autozones. Large evap leak. I have removed the fuel cap and cleaned the o-ring on the cap. Cap has been tight when message has popped up so I don't know if it is the cap. Don't mind buying one if I think that will fix problem but I also see posts associated with P0455 on an evap solenoid. I removed the solenoid that other messages referred to and blew air through it while actuating it with 12VDC to see if i could clean it out but maybe not as light is still on.

 

What is the recommended fix for this code and what part(s) do I need and part numbers if anyone can help. I may call the dealer and ask what they charge to read the code but I don't expect they will show a different code than AutoZone.

 

Don't mind doing the repair/replace myself if I know exactly what the repair is and what parts I need. I've seen fixes that referred to P0442 and P0449 codes so I want to get the right parts to fix the 455 problem.

 

Any help would be greatly appreciated.

 

Thanks,

 

Mike in AL

[8.1HD/ALLISON]

More than likely the evap vent solenoid is full of dirt and not sealing. Very typical problem. If you get off the blacktop they tend to collect dirt. There is a bullitin on replacing the vent solenoid and rerouting the filter to the top of the tranny, however this didn't really solve anything. If you do a lot of rock roads or dusty climates, I would run the filter all the way up to the master cylinder and tie up there.

[Bob D]

 

 

...I removed the solenoid...and blew air through it while actuating it with 12VDC to see if i could clean it out but maybe not as light is still on...

Did the valve "seal" tight when de-activated?

[peterbilt744]

I had a P0442 code originally on my 06' 5.3L silverado ext. cab and it kept giving me the tighten fuel cap message and then after about two weeks it turned into P0455 and P0446. I did alot of research and came up with it being the evap valve canister. I replaced the old one with a ac delco part #214-2149, about 1 1/2ft 5/8" heater hose and 2 hose clamps and havent seen the service engine light since. I talked to numerous gm dealers and they kept telling me that was the wrong part but come to find out they have a new up dated part and the only difference is that it has an extra vent that you run up under the hood. For the original part i paid $14.00 from amazon and the new up dated part gm wanted to sell me was like $170.00. I didnt have to replace the gas cap either. Hope this helps.