Car not starting up right after getting gas

I currently own a 2006 Chevy Cobalt. For the past few months it had a problem that every time I get gas when I go to start the car up I have to pump the gas pedal and crank it at the same time to get it to start running. Once its running I have to either get driving pronto or sit and it park and accelerate it a little for a bit to keep the car running. If I let go of the gas pedal the car will clunk and shut off. If I drive off after a few blocks it’ll work fine and I won’t have the problem again until I put more gas in it. Occasionaly when at a light or stop sign while in drive the car will clunk a little but normally stop after few seconds.

I went to AutoZone and they told me I had a pressure thing (can’t remember fully) but to replace the gas cap. Which the car tells every so often to check my gas cap. Well 4-5 gas caps later problem still there.

Any ideas on what it could be or how to fix it, last resort is to take it to the mechanic and pay a nice bill for a fix.

And what codes did the AutoZone guy download from your ECU? If you can’t remember, have it read again and keep the shop order with the codes on it.

The guy at the Autozone was suggesting that you have a Evaporatib Emissions System (EVAP) problem. Attached is a diagram of your system. Perhaps he’s suggesting that the “EVAP canister” is saturated and the tank cannot breath in…and thus cannot pump gas out. If you “top off” your tank, that can happen.

But, before assuming anything, get the codes and post them here.

busy weekend just got back to the forum. ill take it to autozone to get the codes again. but this morning the check gas cap beep on the display again. joy… will post the codes later tonight.

ok sorry for late reply i went and got the codes for the check engine light that lady said 3 of them came up twice so the ones with (2) came up twice. if that makes sense.
p0128, p0496(2), p0442(2), p0455(2)
these are the codes in which the lady told me. hope this helps in helping me fix the problems.