All my codes are fixed since I replaced the vapor canister. The only code I got now is P0455

 

Tighened the clamp on the filler hose and put in new throttle body gasket and made sure they was all tight will know tomorrow if that fixed the problem.

 

Good to know. Something you want to be clear about for people trying to help you diagnose.

 

I am having problems with my 08 as well with the large evap leak. I don't remember the code number. I can smell gas too and it seems to be coming from the evap canister. Can this be changed without dropping the tank?

Also should I change the purge solenoid too?

 

Yes you can change the evap canister without dropping the tank. All it takes is to remove a bolt on the canister then slide it out of the track it slides into. Then remove the lines. If you get a new evap canister it should come with a new solenoid mine did.

 

Thank you for the info. I will order parts and try to install myself then. Save me some labor costs.

 

I failed to mention that today and the last time I filled up, it didn't want to start. Cranked a long time. Also for the first time, the fuel pump clicked off at 3/4 tank and acted like it was full. For a couple weeks now, I have had to turn the key on for a few seconds before I cranked it over or it would crank for a few extra seconds. The EVAP system is the only codes that are being thrown. I hope this will fix all the problems.

 

You more than welcome I changed out my EVAP canister in less than 20 mins. The Purge is on the driver side under the hood it also is easy to change.

 

Are you sure the gas smell is coming from your evap canister? There is a recall for leaky gas pumps on Cobalts of certain years. Mine started leaking at about 100,000 miles. This combined with your comment below about having to turn the key on for a while to let the pump prime, you could be losing fuel pressure through a leak. If you have this problem though when you get under the car you will easily be able to tell is there is gas dripping down the side of the tank. Just wanted to give you a heads up on this potential issue.

 

Thanks, I will check. Mine has 122,000 miles on it. I have been having the code come up for a while now but not having problems with daily running. I was thinking that the prime problem may have been from the purge being open and that was where the pressure was being lost. But now that you mention it, a leak at the fuel pump probably would show up as a "large leak purge system" I ordered the canister, filter, vent hose, purge valve solenoid, and canister vent valve solenoid from Rock Auto last night for $216.96 shipped. I will know more when I get into it. I never got a recall on the pump, maybe it was a dealer information type of thing. I assume that the tank will have to come down to replace the pump. Some cars have the trap door to change it from above, ours probably don.t have that. I will be getting into it Friday when I have a day off if the parts come in.

Thanks again for the good information. I used to do more work on my vehicles when I was younger and more flexible but this I can do I think. If the pump needs replaced though I will take it to a mechanic.
Bad thing is that my Avalanche this week had to have the fuel pump replaced because of rusted fuel lines leaving the pump. I see on the parts pictures that the Cobalt pumps are plastic at least so rust shouldn't be a problem.

 

I never got a notice for the recall. When my pump started leaking I started looking online to find what the cause was if other people had the same problem. Then I discovered there was a recall. I was planning on replacing it myself up until that point but was glad to let the dealership do it for free. I called them up and made sure I was covered before I brought it in. They only cover it if the car was sold in certain states. Something with cold or hot temperatures causes the failure.

 

Thanks again, I searched and my state isn't a part of the recall. Looks like if it needs replaced it will be up to me.