Help needed.


I've been throwing the p0455 code for awhile now. I have replaced the gas cap, and I have also replace the evap vent solenoid. Neither of those have resolved the issue.


In addition to the code, I often have trouble filling the tank with gas, without it stopping every 2 to 3 gallons. It's also sometimes difficult to start the suburban on a warm day w/out opening the gas cap to let fumes escape.


At this point, I think the next step is to replace the vapor canister. I ordered and received the part from rockauto.


Has anyone replaced this before, and is this something I can do w/out dropping the tank?


Any information would be great before I put the car on jack stands and crawl under it again.


Thanks.

 

you don't have to drop the tank. the canister is in different locations depending on if you have a 1500 or 2500.
hopefully, you got the revised vent valve part that relocates the air inlet filter so the new vent valve won't fill with water. the tsb is #09-06-04-028D -1500 series only.


I think you have 2 separate issues.


Blow out the entire vent valve fresh air line to make sure its not clogged. air has to vent from the tank to the canister, out the vent valve and out the air intake hose. If its blocked at any of these points, you will have a slow refueling event.


are you getting a hard start after refueling? I think this is a stuck open purge valve which will set the p0455 also. to verify this, remove the purge valve hose and blow into the purge valve...air should not pass. A stuck open purge valve will allow fuel vapours into the intake and create a flood condition.

 

Tech2,


Thanks for the reply. I did get the canister replaced, reset the codes.... p0455 came back within 120 miles. So far I have replaced the gas cap, evap vent solenoid, and the vapor canister.


You mentioned the purge valve. Where exactly is that? I don't see anything like what the part from rock auto looks like.


As far as hard starting, that doesn't happen after a fill up, but it does happen quite a bit, especially when the temps outside get above 80. It cranks for a long time, or I have to crank it twice. If I turn the key to on twice before trying to crank, that helps. It almost seems like it's not getting enough gas?


Any suggestions.
Thanks.

 

attached, You might also want to check your fuel pressure as it can be a cause of the hard starts...