Error code 455-Gross leak | Ford Explorer Forums - Serious Explorations

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Error code 455-Gross leak


September 23, 2007
Reaction score
City, State
N.E. Pa
Year, Model & Trim Level
98 XLT
This is another check point for the annoying error code 455. "Gross vapor leak in the Evaporator System". This code usually points to the gas cap as a first check. If the cap isn't the problem, the filler neck, as was the problem for me is a check point.
I have a 98 XLT 4.0 SOHC. Upon original inspection of the neck, it looked old but OK. All other hose inspections looked fine. I decided I would need to drop the fuel tank to find the compromised hose. When I started to disconnect the filler neck hoses to the fuel tank I found the problem. There was a large hole in the filler neck under the hose on the larger tube, but before the hose clamp. I never leaked gas from there when filling the tank but obviously the system couldn't hold vacuum thus the error code.
My quick fix was to sandwich the hole with another clamp placed above it.
I'll replace the neck when I find one.
Hope this helps someone being bothered by that code.

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That's a good "heads up." Thanks for the info. I'm currently dealing with the opposite problem; a code P1450, "excessive vacuum." I've checked and replaced almost everything in the EVAP system. Just dropped the tank and am going to replace the tank pressure sensor. If that doesn't fix it, there will be black tape over the

Thanks B33 for the post.:thumbsup:
I've been having problems with my 2000 Explorer getting an error for a small fuel vapor leak. I've cleared the error with my Actron scanner. I could sometimes smell gas near the gascap, so I replaced it, but still no luck. Now I've gotten a light on my dash, besides the check engine light, that says to check my gascap. I found that the plastic insert for the fuel filler neck has a couple of good cracks in it. Need to replace it but at $267.00 at the dealer for the whole fuel filler assembly, kind of hard to swallow. Anyone have a good, cheap fix for this? Considering some kind of gas resistant, two-part epoxy to repair it.


Well while putting gas in the tank yesterday, I bent down and looked into the wheel well just for the heck of it and now I have gas on the frame just below the clamps I put on the filler neck and my CEL is back on. I'm trying to find a filler neck online but I can't find one for an Explorer. I'm gonna hit a couple local junk yards this week and see if I can't get a decent replacement. I'm not sure what years have the same neck so I'm hoping they can tell me. If all else fails, I will remove the neck, cut it back to good metal and replace the hoses with some longer hoses to compensate for what I cut off. I'll let you know how I made out.

When you replace the rubber hose and install your hose clamps, consider using two clamps on each end, with the tightening screws 180 degrees out from each other. This will help ensure a good seal. Might not hurt to wipe a bit of RTV sealer on the metal tube, too, before sliding the rubber hose over. Might be overkill, but at this point, why not?
As far as what year Explorers may have the correct filler neck, what I saw at a junkyard today looks like the first generation Explorers have an all metal filler opening with a large metal tube to rubber hose inside the fenderwell. The early second gen Explorers are that way, too. The 1998-2000 Explorers seem to have the plastic filler opening with the large metal tube reducing it's size (steps down in size before the rubber hose) inside the the fenderwell.

Tanks for the info. I found an online junkyard that has a neck for $60.00 delivered. I'm waiting on one more price from another online junkyard. Still didn't price one locally. I'll use the online prices for bargaining power. I'm probably going to cut back the old one first and use a longer hose to make up the difference. The neck is only rotted at the very end so we'll see. I did try to sandwich the hole with 2 clamps but it didn't work. I think because the hose is so old the puddle left between the 2 clamps seeps through.
I probably will try the silicone under the hose. My neck is a larger pipe from cap and then splits into 2 smaller pipes(1 larger than the other) then to 2 hoses to tank. Thanks again.

The junkyard I went to is part of a national chain called Pick-N-Pull. I don't think they ship parts. The one I go to charges customers $2.00 to walk the yard. They've gotten better at giving you specific prices for a given part. When I went there, they pulled up a picture of the filler neck on their computer and gave me a price of about $24.00 for the part, so much better than the $267 the dealer wanted. Unfortunately, they have no clue what they actually have in the yard, so my searched was for naught.
I live in the Chicago area and there are 3 Pick-N-Pull sites for me to visit, but I've only gone to the closest one in Summit, IL. They have yards in Wadsworth, IL and Hammond, IN.

Check out their site.They've got 38 sites between the US and Canada.
Good luck on your quest. I just got back from a 4 hour drive with my Explorer after clearing the dash warning lights and putting a piece of duct tape over the crack in my truck's filler neck. No problems, but I will be looking for a filler neck again, soon.

Finally, 200+ miles and no more error code. My final fix was to cut the neck back to good metal. Finding the same Diameter hose was impossible. None of the parts stores carried it and the stealership would only sell me the entire neck/hose assembly for $265.00. A local equipment rental place helped me out. The mech there had leftover parts from kits they use to extend the fill lines when people lift their trucks. I used the piece he gave me(no charge) and sandwiched it into my fill line. That way I was able to keep the correct size ends. Worked great. Now onto some minor body work.