It's been a long time and it's been one of those things I haven't paid much attention to, but recently my truck has done like a little humming noise when I'm crusing in the 20-35 mph range.

The codes I am having problems with are:

P0456 evaporative emission system leak detected (very small leak)
P0440 evaporative emission system
P0441 evaporative emission incorrect purge flow

The only thing I have replaced is I think the purge solenoid underneath the hood by the battery. Idk what it could be so I hope you guys have had the same problem.

 

Mine threw a couple evap codes once. I think it was the p0456 and the p0457 (what ever major leak is). It may have thrown a p0440, but i made sure the gas cap was tight and all the hoses around the tank and box looked good. Well after clearing it out a few times it finally stop coming on. That was 20k miles ago and never done it since.

 

Mine had both small AND large leak (whatever #'s those are).
It's cold here, I aint crawling underneath now.
been since Oct. The engine lite is now out. Haven't checked the current memory codes.

 

sounds like you really need to check all the hoses to and from the charchol canister.

If they're cracked or loose or broken all the codes you have will be set.

 

My evap leak was due to a bad fuel pump assembly ,the whole upper part of sender was cracked . Replaced pump assembl fix that problem but about 4 months later had to replace unit again because check valve failure! I've had very poor luck with my dodge . It doesn't even have 50,000 on it yet!

 

nvld pump sounds to be the culprit I had the same issue on my 03 4.7 1500. Shop wanted 400 to fix so I thru money at it new purge and tubing all thew way around 1st waited month and still had cel. Went to napa (only parts store aside from dodge that carried the nvld) was like $30 took 5 mins to pop on and cleared the light next day and about a year with no light.

 

Not the first time I heard this!! I ordered it up from napa with a fresh filter and the 2 hoses I order from dodge! I'm gonna replace these and hope it works. Ill keep you guys posted!!

 

if the NVLD doesn't fix the problem, I would get a can of brake cleaner and start spraying around the vacuum lines and intake manifold while the engine is running to check for vacuum leaks. The engine will sound sputter when you find the leak.

Just don't spray it on any sensors or electrical components if you can help it.

 

Okay thanks ill try that 2nd

 

That is a good idea.
NVLD?