P0440 code

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AdventureDad

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2008
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while chasing down an intermittent P0440 and gas cap code on my new to me 08 4.7L 1500 4x4, I inspected the hoses to the charcoal canister. I found a quarter sized hole in the leak detection pump air filter (black V8 juice can sized thing just up from the charcoal canister). Instead of buying one and waiting, I fixed it. Shade tree style. It had some dust and pebbles on it. Blew it clean with nitrogen, then I cut some thick flexible plastic, rtv’d the perimeter, being careful not to obstruct the hole, or suck any in. Put the new plastic patch on. More rtv on top to block any small holes. I covered it with mastic hvac tape. I wonder if that was the cause of my vacuum leak. I don’t even know what it really even does.

Hope it works!
 
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OCDTech

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while chasing down an intermittent P0440 and gas cap code on my new to me 08 4.7L 1500 4x4, I inspected the hoses to the charcoal canister. I found a quarter sized hole in the leak detection pump air filter (black V8 juice can sized thing just up from the charcoal canister). Instead of buying one and waiting, I fixed it. Shade tree style. It had some dust and pebbles on it. Blew it clean with nitrogen, then I cut some thick flexible plastic, rtv’d the perimeter, being careful not to obstruct the hole, or suck any in. I covered it with mastic hvac metal tape. I wonder if that was the cause of my vacuum leak. I don’t even know what it really even does.

Hope it works!


My brother years ago had a late 90s Ram 4x4 had a large leak code in it. I looked around and to my surprise the location of the charcoal canister on a few years of dodge was on the OUTSIDE of the frame passenger side where the cab meets the bed. We took it out it was busted bad. Went to the local U Pull it auto and got one. Upon getting it home i seen a small crack in it, this was the only one the junk yard had. I was doing model RC airplanes at the time and we use two part epoxy to fix our planes. So i epoxy the crack, let it dry, do a vacuum test with a hand pump, and all good. Re install clear the code and its gone.......for a couple of weeks. He says i have a code again, i pull the code same thing. I was like dang, another leak. So i go look at the charcoal canister to find......its GONE!!!! Boy what did you do, i swear to you all, he said me and grandma went riding in the creek the other day. Shook my head. I thought you would like that story, hope you have your leak fixed.
 
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AdventureDad

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2008
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Lol ... I’ve seen River Monsters... scary stuff lives in creeks. Well I’m hopeful, but that dang gas cap code came back. It’s a new gas cap and I’ve heard the oem ones are the only viable option for our trucks. I just got the truck a few weeks ago and noticed the gas cap was new. Never really thought about it. I put Vaseline on the gasket, and that worked for 2 days. Guess I’ll have to shell out some $

Btw...that’s my kind of Grandma!
 

OCDTech

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Yea try OEM, i had a weird issue on one of my subarus the other day, all the lights came on dash cruise didn't work, code really didnt correlate. Fuel level sensor circuit high or something. Anyway all i did right before that was change the gas cap to non OEM. Put the OEM back on,reset light so far so good.
 
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AdventureDad

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2008
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So... update on my P0440 code. I've checked all hoses (no cracks anywhere I could see). When I start the truck in the am every other, or every 3rd day, after sitting all night, the truck will idle for 2-4 minutes while I fasten my belt, get my coffee secured, etc, the CEL will pop on. If I clear it via removing the battery terminal remove and turn-key-to-start for 30 seconds, it won't come on again that day. Another oddity, is once the CEL does come on, if I don't clear it, it drives the same, but my overhead mpg drops faster than if the code doesn't come on. Like I am getting worse gas mileage. I haven't run a whole tank and calculated by hand yet to see if it's just a computer discrepancy, or is the truck enriching the mixture.

Just some more data to see if any of you guru's have any advice.

Regards;

Adam.
 
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