I looked this up online & found the following.

Trouble Code: P0442
EVAP System Medium Leak Detected
Trouble Code Conditions:Monitor with engine running. Cold start test. Fuel level more than 12%. Ambient temperature between 39-89F (4-32C). Closed loop fuel system. Test runs when small leak test is maturing. The PCM activates EVAP purge solenoid to pull EVAP system into a vacuu
Possible Causes:

• Intermittent condition
• Vacuum hoses, connections or switches have come loose or malfunctioned
• EVAP emission system has a leak
• EVAP purge solenoid operation has malfunctioned
• NVLD switch operation has malfunctioned

So what does that mean? do I need to replace the PCV valve? EGR valve? Add some gas (less than 1/4 tank)?

Where would one find the EVAP purge solenoid to test it? Or the NVLD switch?

 

it could be as simple as not having your gas cap on all the way. but the evap canister is under the drivers side seat under the cab. you cant miss it. mine has the same code, its just the cracked hoses and such. i will probably never fix it.

 

i had the same code and a new gas cap fixed it for $10. if the old one has a hard rubber ring its probally toast. not saying there couldn't be another leak tho.

 

Like thunder said, check the hoses around the evap canister Chances are one is cracked. Just replace it if the gas cap doesnt fix it.

 

My Dakota threw a similar code, P0441 which is for a small evap system leak detected. It was after I was in a wreck back in March. I tried a new gas cap, CEL came back on 2 days later, had the same P0441 code. I put my old gas cap back on. Then I checked the charcoal canister and its rubber hoses under the truck, all looked good but there is really no way I know of to test the canister without Dodge dealer diagnostic tools. I have heard you will smell strong gas fumes outside the truck if and when the canister goes bad. If you like to top off the gas after filling it up, eventually it will ruin the charcoal elements inside the canister. The canister can not handle the excess gas vapors.

I kept looking for the cause of the P0441 code, cut off a cracked end from one of the evap system hoses under the hood at the green evap test port, the code came back a day later. Then I started thinking. In the wreck in March, the at-fault driver hit me in the left front corner/left front inner bumper area on my truck, and he hit me hard enough to break my battery tray. The Natural Vacuum Leak Detection Pump (NVLDP or LDP for short) is mounted on the bottom side of the battery tray. I figured if the guy hit me hard enough to break my battery tray, it probably broke the LDP too. A new LDP costs $130.00 at the Dodge dealer here, and it is a dealer-only part. I did not want to spend $130.00 and not have it fix the problem so I bought a used LDP off a "Cash for Clunkers" Dakota at a local junk yard for 20 bucks. I also replaced all but one of the evap emissions hoses under the hood with $7.00 worth of rubber fuel line from Advance Auto Parts. The evap hose I did not replace is the larger diameter hose going from the LDP to the hard plastic hose on the firewall back down behind the engine. It looked like it was still in great shape, and it is also a dealer-only part, probably costs every bit of $100.00. And I replaced the 2 little right angle hose pieces at the purge solenoid with replacement hoses also from Advance. Then I did a hard reset on my PCM and the CEL has not come back on since.

The NVLDP switch is an internal part of the LDP itself. The PCM commands the LDP to check the emissions system for leaks and leaky evap components every so often. I think on my 3.9 the LDP checks for leaks every 70 minutes of engine run time. If a leak is detected, the PCM sets the CEL and will throw a P0441 or P0442 code. The purge solenoid empties the charcoal canister into the intake at certain intervals to burn off the stored fuel vapors. I have read and heard when you get one of the P0441 or P0442 codes, most of the time it is the LDP that is bad.

The purge solenoid on my truck is mounted up on top of the fender liner inside the engine compartment behind the the left headlight. I personally don't know of any way to test either the LDP or the purge solenoid. The dealer uses a smoke machine hooked up to the test port on the emissions hoses under the hood to inject smoke into the evap system. When there is a leaky component in the system, the smoke comes out of the cracked component, kind of like putting a flat tire in water to watch for the air bubbles to find the nail or hole in the tire. Who knows how much a dealer would charge to do the smoke test for you though.

The P04xx codes can be hard to get rid of. There is a long list of possible causes for the same code. Dakota's are known to have the rubber evap hoses at the charcoal canister to crack and split, so you could start there first. Even the slightest and smallest crack in an emissions hose can throw the P04xx codes so check all the hoses at the tank and under the hood very carefully.

I don't know what engine you have, but my 3.9 does not have an EGR valve. And if you have not replaced the PCV valve, they only cost a few bucks. If you are not burning oil and the old PCV rattles when you shake it, the PCV is probably OK but it's good cheap insurance to just replace it anyway. Personally, I replace mine about once a year or so. I don't see how having a low amount of gas in the tank can set a P0442, but I guess anything is possible. It's a good idea to always fill up again when the tank fuel level gets to 1/4. That keeps the level of fuel surrounding the fuel pump sufficient to keep the fuel pump cool, and it helps keep dirt and debris out of the fuel filter and the fuel filter sock (and out of the pump too). I have seen a lot of posts about fuel pump failure on Dakota's and most of them (including my own) only last about 120,000 miles anyway.

Jimmy

 

**Bump**

Bumping the post here because I just saw my reply was post #666. I don't need any satanic gremilins plaguing me or my truck...

Jimmy

 

we already have the mark of the BEAST on us. (at least here in the US)

we have had it almost since birth.

you cannot get a job or anything else without a social security number.

KillerKilgore

 

WOW! THanks for all the replies. I'll spend some time today under there looking for cracked hoses. I sure hope its something simple like that & not a money pit.

As far as the mark of the devil - every bar code contains the number 666.

If you find a bar code with the number 6 in it you can see - there are two narrow lines that represent the number 6 || . There is a double bar at the begenning middle and end of every bar code.

So - like a crazy guy at work told me once - if you buy anything with a bar code you are accepting the mark! Ha - that's quite a stretch for me - but to each his own.

 

OK - so I dug around under there a few minutes ago - the hoses all look brand new. They are soft & pliable & have no cracks or dry rot. The canister looks OK too - but hard to tell.

Since it was a 442 code - medium leak - I'd say the NVLDP is probably shot - I checked it too - soft hoses - even the 90's - that thing looks simple to replace - I'll search around & see what I can find for it.

I plan to drive this truck for a while - so I want it to work correctly - besides its not very old despite the miles.

 

My local dealer has the NVDLP for $60 in stock - on my way to get it - I'll keep you up to date.