2000 Dakota / P0442 code

Hi all,
I've seen lots of posts regarding the P0442 code. I've got this code and need to look into it. But was just wondering if some background data on my particular issue might trigger any thoughts of where to look.

I live in central N.Y. Last year (2005) in the Sep. / Oct. time frame my check engine light came on. I remember it was an unusually warm but damp morning. At that time I took the truck to AutoZone and they did the scan test for me. Said the code showed an small evap leak and typically this was because the gas cap was not tight. They cleared the code and told me to ensure the gas cap was always tight. Then they said if the code comes back within 500 miles to come back and they'd dig in a little more. Well...the code came back within 2 days. I was going to bring it back to them, but 2 days after the code came on it went off by itself.

The light never came back on until just a couple days ago. Once again it was unusually warm for this time of year in central N.Y., and it was also very damp. I remember going out to the truck and reaching in and starting it, then left it running while I went back into the house to grab something I'd forgotten. When I came back out I remember a slightly strong gas odor. Didn't think anything of it at the time. But as soon as I started driving the truck I noticed the check engine light on. When I got home that night I un-hooked the battery cable, turned the ignition key to the run position for about 30 seconds and hooked the battery up again. I then drove the truck for about 10 miles and the check engine light was not on. However, the next morning when I started the truck the light came back on and has been on ever since. Probably about 3 days now.

I started some research and found this site. Lots of good data regarding this code. So I'm thinking my plan of action will be as follows.
1. Find the evap canister and hoses that connect to it through the tee that has the service port. Check for any cracked hoses.
2. Get a new gas cap from Dodge.

But my real question(s) is this.
Since I could really smell gas fumes, wouldn't I have gotten a code that indicated a major leak in the evap system? I believe the P0442 code signifies a small leak. I would have thought I would get a code that indicates a gross leak.
How about the weather? This only seems to happen when the weather is warm "relatively speaking" and very damp. Would this type of weather point to any particular location? Hoses or gas cap or something else?

Thanks....Bill

you're on the right track!

Today I went over all the hoses / connections I could get to. As far as hoses go, I didn't see anything that looked even remotely bad. In face I was quite surprised. Considering all the crap that gets put on the roads here in central NY I would have thought the condition of the hoses would be bad. But the rubber hoses and plastic hoses all look brand new.

Then I figured it was time to replace the gas cap and give that a try. I know there's been talk about using only true Mopar caps, but for the next couple days I won't be able to get to a dealer. And I really want to try it. So I picked up a new cap at Advance Auto. It's a Stant brand. Seemed pretty good. We'll see I guess. One thing I immediately noticed is it seems to screw down much tighter than the original. Seems to take more force to get it to click the suggested 3 times.

About the only thing I did see on the whole Evap system that made me nervous was the gas filler. There's a metal section of the filler neck that breaks off into 2 pieces. One is where the gas goes to the tank and the other I assume is a venting pipe. These attach to rubber hoses which lead into the tank. I noticed the metal section of this is in pretty rough shape. Very corroded. I think if the gas cap doesn't solve my problem I might look into replacing this metal section. Seems like there could possibly be a pin hole in that and I'd never find it visually. Probably best to just change it.

I'll let you know what else I find out.

- Bill

no it's probably best to get somebody pinpoint the leak hen replace the part that is leaking, guessing on a filler neck because of appearance is far from the best way!

Just an update. I haven't driven my truck very much during the past couple weeks. Been on vacation and driving my wife's vehicle. But since I replaced the gas cap the check engine light has not come back on. I'm hoping I'm not jinxing myself by posting this

Hopefully all is well....

Jeff...thanks for all your help on this site. You've got great input.

- Bill