Hi and thanks for your help

P0442 this time

3 years ago I had the truck smoke tested, it had a broken rollover valve on the fuel tank. I fixed that with JB weld and that kept the check engine light off long enough to pass smog.

Then the light came back on, and now I have to smog it again. I replaced hoses from the tank to the charcoal canister, under the hood around the leak detection pump and purge solenoid and to the motor.

I had the system disconnected from the motor entirely for a while because with it hooked up when you'd start the truck cold it would start to stumble and buck.

I thought i vacuum tested the LDP, and I put like 5psi into the lines and listened and felt for leaks, but hell I don't know

I wonder if the leak pump or purge solenoid could be bad. the missfire when it's cold makes me wonder.

and yes I have a new gas cap

Cheers

same thing on my truck. I squirted some wd40 in the hole for the spring on the gas cap and used a nail to push the vent plunger in and out it was jamed up and now its free and no more code. I have been told it can take up to 7 days for the codes to be cleared without pulling the batery cable. Also I have made it a habbit to spin the gas cap three to four exta turns when putting gas in. Als i was tyold to never leave the truck runnig while filling the tank that give the computer a big vacume leak and make the light go on as well.

wouldnt be uncommon for warpage on the top of the tank and leak around the fuel pump module...also check all the vacumn hoses to the purge valve, the ldp, canister etc any small crack can turn on the mil. also not knowing where you are if you have a rust hole in the filler tube...thats pretty common in these parts

my 06 ram had a small evap leak. i put on a new gas cap and reset. a week later the code for large leak popped up. i replaced the purge solenoid and replaced the short hoses that connect to it and blew air(low pressure) back thru the line that goes back toward the gas tank. reset again and no more problems.