Getting check engine codes P0442 & P0455 on my 01 RAM. I tightened gas cap and messed with the evap hoses but could not find anything. What could it be. I reset the codes by disconnecting the battery and they came back after 40 miles.. How long does it take for a code to re-occur??

Thanks

 

there is a canister under the bed of the truck, mounted to the frame, you may have damaged it or one of the vacuum lines going to it. If you wheeled it at any time, it is possible it got damaged. If your truck is setup like mine, there is next to nothing in the way of vacuum lines, disconnect them from the intake manifold and put a vacuum guage on them and see if they hold a vacuum. if not, you probably have a leak somewhere...

 

My mom, yes my mom, had the same thing happen to her and all it was was a small piece of vacuum hose.

 

Well, I tried to check all the hoses and make sure they were tight. Also cleaned gas cap and top of filler tube. The green cap with the valve under it in the engine area near the canisters was tightened then I reset the battery so we will see how long it lasts..

 

so far it has been 200+ miles and no code...

 

Well 337 miles and the check engine light returned. Guess I will have to buy a vacume gauge and check things out.

 

I recently had the same codes on my wife's Durango. I inspected all the vacuum lines between the gas tank and the engine, and found a 1" diameter line was split at the very top on the connection near the front of the gas tank. You would have never known it was split without lightly pulling on the line. The line popped right off. The split was long enough, that I know it had to be leaking there. I just trimmed the split portion off and reinstalled it. I added a hose clamp to the line this time; which might help it last longer. Take a look at yours and see if this is the same problem. Hope this helps!!

Wayne

 

Well instead if a vaccum gage I got a new gas cap and it has been good over 600 miles. This may have been it. I will report back if it fails.

 

is that stupid or what? a gas cap causing all your grief. why cant they come up with a code that points to the gas cap?

 

$12 dollar gas cap was the fix. Has been good for 3k miles.