Another EVAP sys check engine light yet different

[Sjyellowjeep]

I'm a newly registered user but haveused the forums for many years). Anyway....

I have these codes on my 2001 TJ 2.5 and would like some advice.
P0441 (EVAP purge flow monitor-insuff. or excess. flow detectected)
P0442 (Monitor med. leak detected-a small has been det. in EVAP)
P0443 (EVAP purge solenoid circuit-an opened or shorted condition det.)
P0455 (Monitor Large Leak Det. In EVAP sys.)
P0456 (Monitor Small Leak detected in fuel unit)
What is different is that a t amount of gas vapor rushes out of the gas fill inlet when I remove the gas cap even if it is on for just half a day. I had it smoke tested and no leak was found. I replaced the purge valve and solenoid (perhaps bad?). The leak codes don't make sense to me sense vapor is blowing out in such a rush ( I don't even secure the gas cap completely because I don't won't to put uneeded pressure on the tank or EVAP system, or have a Jeep bomb) If it's not that what else could be blocking it? Any one solve a similar issue? Ideas? Thanks in advance.

 

[John Scoggins]

Is the outlet to the charcoal canister or the canister itself plugged up? One way to check is to blow thru the system with the engine off, just pull of the line from the purge solenoid and blow towards the tank, the system should be open to the atmosphere thru the charcoal canister. When smoke tested did the smoke come out of the charcoal canister, it should have if the system is/was not plugged up.
Vapor should not rush out when the gas cap is opened, do you have some trouble filling the tank form the pumps by chance?

 

[Sjyellowjeep]

Update: I took the advice of Scoggins and pulled the hose off the purge solenoid. I blew back towards the gas tank and I was able to. I then forgot to plug the hose back in and drove about 10 miles. After plugging it back in the check engine light hasn't gone on for 300 miles. After resetting it before, it always goes on under 20 miles. I don't think this will fix the excessive pressure but might allow me to pass smog.