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P0440/bucking after fill-up


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My car began to occasionally give me the P0440/evap control code about one month ago. I tried tightening the cap without success. When I had it in to the mechanic to give me his opinion on my ongoing P1507 saga (detailed at http://www.ultimatesubaru.org/forum/showthread.php?t=61473&highlight=p1507), he cleaned up the rust around the filler cap a put little lube on it. That kept the light off for a couple of days, but it quickly came back. I replaced the gas cap with a new subie one about a week ago, which kept the light off until yesterday.

 

Something I've noticed in the last month or so, since I began getting the evap cel, was that the car bucks and stutters during steady cruising for the first couple of minutes right after I fill it up. It does this almost every time, then it's pretty smooth until I fill it up again. It's also seems like the gas pump has been clicking off short of filling pretty often when I get gas. It usually ends up somewhere between 3/4 and full, but quite often it fills. I'm pretty sure it isn't just the gauge when this happens, and my MPG calculations usually confirm that.

 

I never top off and I don't smell any gas. I've also noticed lately I can hear (I think) gas in the tank sholshing around whenever I stop hard or take a low speed corner. This might have always been like this, I really don't know. I' think I've seen it mentioned that I should be hearing suction released whenever I take the cap off- I do not.

 

One odd thing that ties into my other CEL/ideling/stalling problem. I noticed when I replaced the cap that the car began idleing a lot better than it has. I've consistently had a problems with the idle dipping really low when I come to a stop, then bouncing back up- replacing the cap seems to have made that stop. It also seems smoother now when I let the gas off than it used to (instead of bucking). It does continue to stall on me sometimes when I come to a stop (and throw the P1507), and that has actually gotten pretty bad in the last week. Stalled earlier making a left turn and the again coming to a stop from speed. Since I've not been having much luck tracking that problem down, I'm going to try and slove this one and hope it could be related.

 

Any ideas on what I need to look at?

 

Thanks!

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Took the shield off this evening. Looks like a call to Jason at Auburn tomorrow-I think I might need a new filler pipe :eek:

Ouch! Thanks for posting the pictures. Can't be certain it's rusted completely through, but with that amount of corrosion it obviously could be, or might be leaking at a hose fitting.

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  • 1 month later...

I replaced the filler tube and shut-off valve. It was a pain, even getting the parts was a pain- the shut-off valve was on national back order, after the guy filling in for Jason at Auburn had to call Subaru to even get a part number.

 

Once I got all the parts, it took a few hours to install. I had to drill out all of the completely-rusted screws. The old filler tube seemed to be a little longer than the new one where it went in the rubber hose for the tank, and I couldn't get it to budge enough to get it out of the rubber hose. My car does have a dent in the corner behind the filler, which might have made this harder than it would be normally. I ended up having to cut the old filler tube to get it out. I broke through the rust to plug the tube (so I wouldn't end up with sparks or metal filings in my gas tank). All I have is a dremel tool, so the cutting took some time.

 

Anyway, I really don't want to have to do this again, ever. As soon as I confirm that everything is working right, I have the idea to maybe fill the everything under the plastic shield with expanding urethane foam. Anyone think this will work, or think I might have problems because of it? It might make it a pain if I ever have to work on it again, but if it's filled with foam instead of mud, I might have to work on it again...

 

Thoughts?

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Just curious,did you replace the filter as mentioned you were gonna do before?

Those of you who live in the salt belt i've heard of something you may want to ponder-clean as much rust if any off that metal part and then spray it with the stuff they use to line pick-up beds,up here comonly called rhino line or wrap the pipe with rubber hose and surround everything with a good sealer.

John

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Just curious,did you replace the filter as mentioned you were gonna do before?

Those of you who live in the salt belt i've heard of something you may want to ponder-clean as much rust if any off that metal part and then spray it with the stuff they use to line pick-up beds,up here comonly called rhino line or wrap the pipe with rubber hose and surround everything with a good sealer.

John

 

i'm thinking roofing tar, some rubber hose and then some kind of plastic shield. but spray on "Undercoating" like said above sound like a good idea.

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Yes, I did replace the filter. I have no idea if it needed it or not, I didn't really see a lot of junk come out when I emptied it. The filter did look old so it needed done either way.

 

The car does seem to be running better and stalling a lot less, but the weather has changed too, so that may be unrelated. It did buck a little after I filled it up last, but I've only gotten gas once since I fixed it.

 

As a side note, the gas gauge seems to be going from full to empty in a much more linear fashion that it used to (seems like it used to only have a couple of positions).

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