Thanks!

 

Hello; My 2004 Silverado throws codes for the same thing every couple of years. My solution has been two fold. I replaced the rubber O ring on my aftermarket locking gas cap. I also put some vasiline (sp) on the rubber O ring. I clear the codes by undoing the battery terminals for half an hour. So far that has worked for a year or two before the check engine light comes back on.

 

I have been having same issue “tighten gas cap” and check engine light PO455. But I was also experiencing the inability to put gas in my tank. Pump keeps clicking off fuel not going down. It was recommended I replace evap canister and vent valve so I did. Cleared code and had no issues except a still random “tighten gas cap” alert. 2weeks later approx 30min after the first fill up since canister vent valve replacement the check engine light came back on. Approx 2 more weeks later when it was time to fill up again BAM out of town and cant put gas in again. Only Got $3 gas in…… 😞🤷🏽‍♂️ Someone please help…

 

Hello; To lowriderdave- May be you need to use the slowest flow setting on the station pump nozzle. That way the fuel goes in slowly and may not shut off the pump. If you already have tried this, I have no other suggestion.

 

I have the same issue with the pump clicking off. The solution I found was to literally just not put it all the way in. Pull the pump handle like half an inch back, rather than all the way in like normal. Works for me.

 

Hello; That is what I do also. I do not stick the pump nozzle in very far and use the slowest setting.

 

5 trips to an auto shop-
1st time-they blew the lines out and found charcoal from a canister that failed & replaced gas cap...tighten gas cap message came back ($700).
2nd time-they blew lines again, found more charcoal...($200)
3rd time--they blew lines again-said charcoal scatter throughout the fuel lines when this happens (no charge)
4th time-the dropped the gas tank so that they could access all fuel lines and clean them out, if that doesn't work suggested to replace all fuel lines ($450)
4 days later..guess what??? Tighten gas cap message has come on every day, and on day four the check engine light came on.
BEYOND frustrating!
Does replacing fuel lines actually eliminate the problem??

 

did they replace the charcoal cannister...no where does it say that

 

Hello; To @eor Two things come to mind. First is a question. Does the engine run OK? Seems that particles of charcoal or any such things will make it to the fuel injectors and maybe clog them in some way.
Second thing is my limited understanding of how the check engine light gets activated. The computer from time to time closes the fuel system to check if it holds pressure. My truck seems to lose pressure at the gas tank cap. If the charcoal canister system ruptured and released particles into the system, then it makes sense that part of the EVAP needs to be replaced. If the charcoal is in the fuel lines it is also in the tank.
I was disappointed when I found there is no fuel filter plumbed into the fuel lines of my truck. Adding one might be good if such is possible.

Also do you know the codes?