Troubling p0456

sometimes they either clog up or just stuck. There is also a similar cut off in the snorkel to the tank, which actually suppose to lock, when the tank is full, to prevent the gas from squirting out.
just a simple question- when you drive and stop. cut the vehicle off, like when you get gas. if you remove the gas cap- do you hear air flow? this is mostly a sign- but you would have to do it immediately after turning the vehicle off, because if it's too long, the pressure goes away slowly. usually there should be no pressure or vacuum.
The ball valve is hard to get to, because I think it's imbedded into the snorkel assembly.
What you can do- and I don't know how much technical equipment you have- if you have a air compressor, take a rag and the air handle and blow air in it, while you close the gap around the handle with the rag- but don't increase the pressure too fast. do it slow. this usually looses the ball and blows the dirt out. Another thing- check at the active charcoal filter, if there is a solenoid valve- pull the connector off and take 12 v and ground wires (best is if you would have a pigtail but if you're careful, you should be good). there should be only 2 pins because it's just a open/close valve. attach the + and tip the ground to the other pin and hear if it clicks. also- if you pull the hose off, yeah- little tricky- you might need 2 people for that- one blows in the tank, the other switches the valve and see, if the valve opens and closes and if air goes through and stops, when switched. that's pretty much all you can do. there is not more to the system.
And I be honest- I never done trouble shooting for that on a RAM, because I never had the issue. I can't tell you where the valve is, but it should be there- either directly at the fuel snorkel or right at the active charcoal filter. as far as logical positions.
If your error code is Gas Cap, that's where you got to check, when the gas cap is ok.

Here a link to some pictures- you should be able to find it with this:

https://www.google.com/search?q=2005+ram+1500+hemi+tank+evap+system&biw=1280&bih=889&tbm=isch&imgil=9o8RAIDO6MCOgM%253A%253But9XAPPSnfiC9M%253Bhttp%25253A%25252F%25252Fwww.******************%25252Fforums%25252Ff170%25252F2004-dodge-ram-hemi-1500-vapor-canister-fuel-issues-11897.html&source=iu&pf=m&fir=9o8RAIDO6MCOgM%253A%252Cut9XAPPSnfiC9M%252C_&usg=__2lp3GyrVEqZvTzAAGy4CqT5yzkI%3D&ved=0ahUKEwjt8LC2sbnOAhVGbSYKHShnDCkQyjcIKQ&ei=i3KsV63_CsbamQGozrHIAg#imgdii=9o8RAIDO6MCOgM%3A%3B9o8RAIDO6MCOgM%3A%3BCHF_C6m3qYh2RM%3A&imgrc=9o8RAIDO6MCOgM%3A

https://www.google.com/search?q=200...=i3KsV63_CsbamQGozrHIAg#imgrc=dP_XjdnfPYtGJM:

This for your 2008 Ram 1500 with the 5.7 Hemi. Other models/years may use a slightly different system.

Theory of Operation

The Evap Purge Monitor tests the integrity of the hoses/tube between the throttle body/intake and the fuel tank. The monitor is a two stage test and runs only after the Evap system passes the small leak test. Stage one is non-intrusive. The PCM monitors the purge vapor ratio and the ESM switch closed ratio. If the purge vapor ratio is above a calculated value, the monitor passes. If the ESM switch closed ratio is greater than calculated value when purge flow is greater than a minimum value, the monitor passes. Stage two is an intrusive test and runs only if stage one does not pass. The PCM commands the purge solenoid to flow at a specified rate to force the purge vapor ratio to update. The ratio is compared to a calibrated specification. If it is less than specified, a one trip failure is recorded. This test can detect if the purge hose is off, obstructed, or the purge valve is not operational.

When Monitored:
After the Evap System small leak test has passed, with the engine running, ambient temperature between 4° C (39° F) and 35° (95° F), with the engine at idle after a calibrated amount of drive time has accumulated.

Set Condition:
If the PCM detects that the purge vapor ratio and the ESM switch closed ratio are below a calculated value, the PCM commands the purge solenoid to flow at a specified rate to update the purge vapor ratio. If the ratio remains below a specified value, a one trip failure is recorded. Two Trip Fault. Three good trips to turn off the MIL.


Edit:

If you have a new cap and a smoke test shows no leaks, then I would take a close look at the ESM switch.

seems like there is a problem with your tank evaporation. can have multiple reasons- either it's the ball-stop at your nozzle which routs the fumes to the charcoal filter or it can also- how you described- that the ball, which floats under your filler nozzle gets clogged up and stuck. the ball is there, if your vehicle turns over, that the gas tank does not run out. you might be able to get to it, when you get your tank out and reach through the hole for the pump. sometimes this happens, when the evaporation valve does not work and the tank gets a vacuum and compresses. How you say, it seems like this is your problem. The clicking, what you hear is likely the soleonoid valve for the evaporation line, which actually closes the line, when the engine is cut off- the sensor recognizes, that there is no air flow and tries to open the valve, which is already open- it will be tacted. Check your evap system. But if you rather ask, instead of try, what people tell you, there ain't nothing anybody can help you with.