Hi all--

First off--Excellent Forum! Many questions I've previously had have been already answered in existing threads over the last several months.

That said, I know there are probably a hundred threads pertaining to evap system leaks and associated fixes, but I had a specific question I couldn't find an answer to.

I had the usual "gas cap" code (P0442) specifying a small evap system leak that prompted a CEL. After replacing the gas cap, the CEL and same code returned about a week later. After reviewing other threads and the Chrysler service manual, I started checking vacuum hoses for damage.

All lines were in good shape with the exception of the rubber section of the line that runs from the bottom of the Leak Detection Pump (LDP) to the top of the Charcoal Canister on the frame under the bed. This is a fairly large rubber hose, certainly larger than some small vacuum line.

My question is:
After a cold start when the LDP cycles and checks the evap system, could a bad hose in the location I described cause a system leak? Does the LDP pull a direct vacuum on the charcoal canister?

For reference, my truck is a 2001 Ram, 5.2, 4x4 Auto.

Thanks for any help in advance. I'm one of those people that is driven nuts by a CEL, even if I know it's harmless!

(I did try to attach a couple pictures of the bad hose in the described area, but I got an error saying I had exceeded my quota by a few hundred kilobytes. Kind of odd, since this is my first post.)

Thanks!
Dave

 

watching----having same problem on my 03

 

Sorry I can't be much help with the real question, but as far as this part goes, it basically meant the picture or pictures total size was to large. They have really strict upload limits.

The best thing for posting pictures is to upload them at free sites like Photobucket or an equivalent, and then post links or use the "img]http://putyourlinkhere.com"/img] method. Just replace the " with left brackets [.

 

It's not the gas cap. Check the lines to/from the charcoal canister. There's also a chance the canister has been soaked with fuel and has to be replaced. That happened to mine, and the code gets activated from time to time.

 

I had the exact same problem you had - and I fixed it.

What ultimately fixed my problem, was replacing the tube from the canister that heads towards under the hood. It was pretty much destroyed, and I couldn't see it until I pulled the canister down.

Don't bother buying hose from the dealer. They wanted an outrageous amount when I contacted them... so I went to the local auto parts store, and bought several feet of fuel line for about 12 bucks.

If I recall... the "hardline" that goes into the engine bay is plastic... so make sure you are careful slipping the new tube on. I used a water based lubricant (KY FTW! )to get it on without too much effort (don't use Vaseline because it will destroy the rubber hose).

Good luck,
Cartman

 

jasonw -- Thanks for the heads-up on the photos; I'll try to set the photobucket account up tonight.

VWandDodge -- Can I rap on the side of the charcoal canister to see if it's full of fuel? I agree, I was always under the impression they were pretty much sealed units, so if it was bad you had no option but to replace. I don't even want to speculate on the price from Chrysler.

EricCartman -- I ended up clipping the bad end off up to some good hose. Though I didn't mention it earlier, both ends of this ~2 foot rubber hose were actually showing the same dry rot, from where it pushes onto the plastic tubing near the frame up to where it meets the pre-formed rubber "s" hose that goes into the LDP. There was enough slack to clip both ends and still make the existing hose work.

I was just curious whether there was vacuum drawn on this specific hose during the LDP cycle. There does not appear to be vacuum on it while the truck is just idling normally.

Thanks for the thoughts so far. There's probably lots more knowledge to garner on this topic from the combined years of experience in this group!

Dave

 

I forgot to mention... if you look around on this site, somewhere you can find the 2001 FSM (at least you used to be able to). It used to be in the "Merry Christmas" thread... not sure where it is now. It will have more detail than you would ever want on anything about your truck.

EDIT: Found the link: https://dodgeforum.com/forum/2nd-gen...-gen-rams.html

 

There is a thread with a link in the 2nd Gen FAQ.

 

Here are a couple photos, the first of which shows the dry-rotted hose before I cut the bad sections out of it, and the second shows where this specific hose attaches to the Leak Detection Pump.

Hopefully I did the image link from Photobucket correctly; if not, I'll try again.


[img] http://s1030.photobucket.com/albums/...edEvapHose.gif [/img]

[img] http://s1030.photobucket.com/albums/...temDiagram.gif [/img]


Thanks!
Dave

 

i started with a P0442 awhile back, and after screwing around feeling lines and messing with the gas cap, it turned into a p0455.

initially i proved the gas cap was bad by placing it inside a ziplock bag (as a gasket) and reinstalled. this didn't set off the CEL. however, replacing cap didn't fix my problem and i found a cracked hose at the purge solenoid on passenger side inner fender.