I am new to Dodge products and have a 03 Durango SXT 4WD, 4.7L Magnum engine.
I got a P0440 code and replaced the gas cap, reset, and truck ran great for 4-5 days then the engine light came back on.
the rpms go up and down then the truck dies every time I slow down to stop.
Always starts right back up. Could this be the purge valve or something else?
Thanks.

 

Check under the truck, behind the driver's seat, at the Evap Canister. There are 2 horseshoe-type hoses that connect to it. Look to see if they are cracked. Mine cracked twice. I got them at RockAuto.com for about $4 for the pair.

SJ02

 

+1

Evap leak and most likely a dry rotted hose near the tank and canister.

IndyDurango

 

+2 on the hoses, there is a DIY write up on when i did mine(check the FAQ), this was before they sold the hoses pre-made ftr, i had to make my own hoses to replace them, fuel rated hose.

 

I didn't see any cracks or dry rot, but will replace them anyway, have already replaced gas cap and purge valve. Is there a fuse for the purge valve? If so, where might it be located?

 

Can't find anything wrong with hoses/lines from the gas tank, cannister, leak detector, purge valve. Is there a fuse for the purge valve and or the leak detector since they are electrical parts? If so, where are they.
How do I bypass the emissions system altogether?

 

Uncertain on all questions, sorry. Have you tested your gas cap? I know it's new, but I had one go out in less than 2 weeks. I recently changed out my evaporative filter, too. (May not be the correct name) It's between the battery and the driver's front fender. Comes as a unit from Dodge and is really easy to change.

SJ02

 

Open the hood and follow the evaporative lines, looking where the rubber lines hook into the fittings and around the green screw caps. Where they connect is where the cracks usually are.

SJ02

 

I switched back to the original gas cap. I can only find one green screw cap. Are there more? And I am am not sure what the filter looks like, is it in front or behind the Purge valve? Could the leak detector be bad?
All I know is that the RPMs drop to nothing and engine dies when I go to stop and this is the only code that comes up. Idles good when first started begins to act up when driving.

 

There may only be one green cap. Not sure where the purge valve is, so I can't answer that. The filter housing between the battery and fender is the cylinder-shaped, black plastic piece. There is a filter inside and it comes as one piece. There is a black hose that comes up from the wheel well, under the hood that the filter housing connects to. It does sound like it's an air leak of some sort. Check your PCV Valve also. I'm about to change mine out and it's on the oil filler neck, below the cap.

SJ02