The check engine light is on again on my 2002 dakota 4x4 regular cab with the 3.9 v6. It is throwing the evap system code. Possibilities are the fuel cap, purge solenoid, leak in hose, or evap canister. I have had the fuel cap, purge solenoid replaced, and checked the hoses. I ordered the evap canister, just wanted to know if anyone had any advice on this or had this same problem?

 

its possible you have a leak in the lines somewhere. Have you considered having a smoke test done to find the leak?

 

check the box that is under the driver's side on the inside of the frame rail that's where mine was there r two hoses there that r really prone to cracking if its the bottom hose that is expanded u can just rig it by putting a small piece of hose inside a larger piece then connect it in there.

Edit: the box will be somewhere under the back of the cab

 

What code is stored? You can check the codes yourself by turning the ignition key on (in the run position) and off 3 times and on the third time leave it on and any stored trouble codes from the PCM will show in the odometer display. How many miles on the truck?

If the charcoal canister under the truck has no obvious cracks or holes in it and you don't regularly "top off" the gas when you fill up, I would think the canister is probably OK. Adding more gas to the tank after the hose shuts off when you fill up is what damages the charcoal canister.

SInce you have checked the lines and hoses and replaced the purge solenoid, I would look at the Emissions Leak Detection Pump (LDP). It's mounted to the bottom of the battery tray. You have to remove the battery and loosen the Power Distribution Center so you can move it out of the way to get the battery tray completely out of the truck. Then there are 3 screws holding the LDP in place.

I had code P0441 on my truck a couple months ago when I got my truck back from the body shop after I was in a wreck. I fixed a cracked hose and bought a new gas cap but the code came back 2 days later. In the wreck, I was hit hard enough to break my battery tray. I figured if it broke the battery tray it probably broke the LDP too. The only place to buy a new LDP is at the Dodge dealer, the parts stores don't carry it. At the dealer it costs $130.00. I didn't want to spend that much money and still have it not fix the problem so I bought a used LDP from a "Cash for Clunkers" truck at a junk yard. The donor truck was running OK when the yard got it so I figured the used LDP was probably OK. I installed the used LDP and replaced all but one of the emissions hoses under the hood with 7 feet of fuel hose from Advance Auto Parts. The only hose I left alone was the larger diameter formed hose that runs up over the left valve cover. That one looked OK and is also a dealer only part. I also replaced the little right angle hose adapters at the purge solenoid with parts from Advance. I had to buy a universal hose tee to make up a hose to fit the vacuum port in my throttle body though. That hose is smaller on one end than the other. Then I did a hard reset on my PCM by disconnecting the battery and holding the ignition key in the start position for 30 seconds to clear the code from the PCM.

I did all this 2 months ago and my Check Engine Light has not come back on at all.

Jimmy

 

Really is that true? I have this thing when I fill up my truck after the pump shuts off I always go to the next amount so if its like 47.78 ill go to 48.00

 

ok i appreciate everyone's advice and insight. I got the truck back in September with 82000 miles on it from minneasota. The check engine light came on shortly after and was fixed with running seafoam, this fixed it the first 2 times then the third it didn't. So i replaced the purge solenoid, and that fixed the check engine light from coming on for a few months. I love my dakota, just want it to be fixed. This is the only problem i have had so far and she has about 90,500 miles on her now.A friend suggested i replace the canister due to this problem being on going and could have possibly clogged the canister. I used to have a 1999 gmc sonoma, and i am glad i got a dodge. Its a completely different experience having a dodge. Other dodge owners seem a lot more willing to help or heck just talk haha.

 

"Really is that true? I have this thing when I fill up my truck after the pump shuts off I always go to the next amount so if its like 47.78 ill go to 48.00"

Yep. It causes more fuel vapor than the canister can handle at one time to be forced into the canister. This wears out the charcoal element much faster. Plus it leaves a lot less room in the gas tank for fuel vapors to expand, which will force the excess vapors either into the canister or out past the gas cap seal if it is leaking.

Jimmy

 

I have a similar prob on a 01 4 cyl Dakota. My mechanic sd I would have to take it to a dlr to have the purge solenoid replaced because they have to reprogram it and he could'nt do that. Is that so? I would think the part would cost more (and labor) at a dlr.

 

I need to find this box. It is on the frame you say?

My light started going off because of this too, the first time it went off I noticed one of the hoses had come off of the LDP. I cut the end a little and put it back on, still getting the light though.

How exactly does this system work? It creates a vacuum on the fuel tank and then makes sure the vacuum stays for a set time? If it does it assumes everything is ok? If it doesn't it throws the CEL?

 

ok, well i found a leak in the hose, just cut the end off and put it back on. the light didnt go off. has anyone else had this problem?