"Tighten Fuel Cap"/P0455 Code

[cheeba]

Good Morning All,

Ok, so I have run into my first issue since the warranty has run out (unless you count the "Service 4 Wheel Drive") which I ignore and it goes away. 

I checked the threads here on the subject code, most said to change out your gas cap.  So I did that with a new GM cap.  Check engine light is still on, and the "Tighten Fuel Cap" keeps coming on in the DIC after 2 weeks of waiting for the code to clear.  I dont like clearing codes.  I'd rather attempt to correct the condition and wait for the vehicle to recognize it.  Flawed?

Also saw where it was recommended to check the vacuum lines.  Can anyone provide a decent diagram to check the fuel lines, or a pic with arrows denoting some lines to check that are most suspect OR even just a description of where the most likely lines would be.  That'd be a start, I took a quick look but didnt really see anything suspect.

And finally I saw where some replaced the vent solenoid but I didnt get that code I dont think. 

Any help would be appreciated.  Thanks again.

[cheeba]

anyone?

[jimbo53188]

clear the codes and go from there,it will be faster than waiting for the system to "recognize" the fix.

[Intimidatoruag]

ditto to what jimbo said .... I had the same issue .... they replaced the cap AND cleared the code .... have yet to see the code again ....

John

[cheeba]

Ok, I'll try that.  Its been weeks and it still keeps telling me to tighten the cap.   Is the only way to clear the code to disconnect the battery?

[Intimidatoruag]

yes ... unless you have a reader that will clear the codes for you .... if not just disconnect your battery for about 30 minutes ....

[cheeba]

Ok so I stopped by the local auto parts store yesterday after work and I reset the code (there were actually 2 codes both the same P0455) so the Check Engine light went off.   On the way into work this morning I got the Tighten Fuel Cap again in the DIC.  So its only a matter of time till it throws another code.

And ideas?  I cant find any of the vacuum lines to check if someone could give me some direction there it would help.  Auto parts guy couldnt find any either so I dont feel too dumb.

[ItsStopher]

Here you go, HTH

Look here too

[cheeba]

That first one I think will help me.  Driving to work this morning the Check Engine went on again.  So obviously the gas cap wasnt the problem.  I'll check the lines.  I guess if there are no cracks/holes in the lines than Im just looking at replacing the evap purge valve and solenoid?

[05HrlyHlr]

I got the tighten fuel cap on my DIC 3 times, then the check engine light came on! I went to check the codes and it was a maf code and some shift D link code  nothing about the fuel cap! I cleared them out and am going to wait and see if they come back on! I wonder why the fuel cap wasnt a code though???

[silver_bullet]

Had that code couple of times.  Never replaced cap.  Took the cap off, tightened it, then cleared codes and it has never happened again.  It's been over a year since that.

[cheeba]

I changed the cap and the check engine keeps check engine keeps coming back, along with the tighten gas cap message.  I definately have an issue that needs to be resolved.  That yellow light is starting to really bother me.

[SurvivalFreak]

Cheeba, I have the same issue with my rig.  I too also replaced the gas cap hoping for the cheap 'n easy fix.  but the CEL comes on and keeps throwin that code.  It's strange though, I will reset it, and go through like 2 tanks of gas before it rears it's ugly head again. 

ItsStopher  gave you the correct links to what could be causing this.  I've gone through them but I have yet to chance the purge valve, ect as I'm a boob at determining what problems are on this truck.  I keep forgetting to take it in when I get the code, I just erase it with my Predator and go on my merry way.  Not the best ider, but I hate that yellow light.  I'll probably get it fixed here when I'm off for a bit at christmas.  Good luck troubleshooting your problem.