P0455 - Is the Dealer Lying to Me?

Contour Enthusiasts Group Archives

I took my 98 2.5L contour to the dealer after seeing the check engine light.

I assumed it might be the gas cap. My wife didn't screw it on all the way and this gas cap has become extremely difficult to put on. I don't know if it is stripped or what but it takes me a good 5-10 minutes to get it on. Its a physical issue.

The dealer got a P0455 code told me the vent valve and i believe solenoid (i might be mistating this) had to be replaced at a cost of $950.

I asked him if a P0455 could be set off by a bad gas cap or a lack of seal there. He said P0455 has nothing to do with it, which contradicts what i've read here. He told me they couldn't even reset the CEL light.

I got home and checked out the gas cap. it was barely on (not my doing though i did tell them to check it). I've ordered a new gas cap and took my car but I'm wondering if i can trust this dealer.

I am also wondering if the thing the gas cap screws into can be replaced in case the new cap still has problems going in.

Thanks. Any help appreciated.

I just had that problem yesterday!

I remembered my gas cap did not thread in right, and it must have set the code. I used some Vaseline on the cap and hole threads, after cleaning the dirt out of them first. Then I could tighten the cap properly. I might just get a new cap if it keeps being a pain. (If you Google search P0455, it shows that code is often caused by a loose cap.) The code did not reset itself when I fixed the cap, I had to use my (fairly cheap,at Advance Auto) Actron code scanner to reset the codes. So far, it is fine. The dealer could certainly reset the codes, it would come back if the cap is loose..

A loose gas cap most certainly can cause this code. Follow this link:

http://www.obd-codes.com/trouble_codes/generic/p0455-evaporative-emission-control-system-leak-detected-large.php

Yes, the filler neck can be replaced if necessary (assumig that Ford has not discontinued the part.

I'm also experiencing a "tight" or hard to screw in gas cqp so please let us know if a new cap solves the problem or if you need the filler neck too.

I have an extra cap if anyone needs it.

Vaseline

, is a cheap solution. I think the cap warps or expands in hot weather. If a new cap solves the problem, I will change mine, too.

Originally posted by alaric:
.... He told me they couldn't even reset the CEL light.

We reset CEL codes all day. Pull Fuses 4 and 11 (in the Power Distribution Box next to the battery) for a few minutes. Of course, if the cap is loose, it will come on again after a few drive cycles.

Same thing happened to my kid's car, P0455. The cause was an improperly tightened gas cap.
FYI, you can go to AutoZone and have any codes read and erased for free.

And, welcome to the CEG.

Doesnt undoing the battery also reset the computer? I had a check engine light for a vacuum leak fixed it and had my dad just unplug both battery cables and hasnt come on since? Didnt know about the fuses. Guess that would have been easier. Well, I had to clean the positive battery post anyway. It was corroded.

Originally posted by contour96:
Doesnt undoing the battery also reset the computer? ...

Yes, it does. But you also lose your preprogrammed radio stations and you have to reset the clock.

yea i had to do that....it sucked

But the fuse thing is kinda cool. I will have to remember that

Thank you everyone for the help. I thought i'd provide an update.

I changed the cap and reset the computer by disconnecting the battery (next time i'll try the fuses). So far so good, no CEL, but i did't drive that far. I'll update again after some miles.

The cap now goes on a lot easier. I don't have to fight with it to get it on. I wonder if the old cap has an issue with heat. It started to become a pain last summer, subsided in the fall and became a real pain this summer.

It would wonderful if this new cap fixes the problem. Regardless, i will certainly attempt more repairs myself.

Good for you. Next time, tell the dealer to refer to this TSB 03-20-3 with the first line stating to check for a loose fuel cap first.

"MANY EVAP LEAKS ARE CAUSED BY A LOOSE OR FAULTY CAP"

http://www.ford-trucks.com/tsb/fulltext/show_article.php?tsb=03-20-3

Originally posted by LUCA:

FYI, you can go to AutoZone and have any codes read and erased for free.

Codes pulled yes, but not every store or person will reset them. Some have told me they aren't allowed to, others just did it without even asking!

This is just a follow up about my tight gas cap. In hot weather the cap would bind so severly that it was very hard to remove or install. Light grease on the threads didn't help much.

I finally replace the cap and that was all that was wrong. I was afraid that I may need to replace the filler neck, but I did not. The problem was fully resolved with a new cap.

Evaporative codes are becoming more and more prolific. Especially as the vehicle gets some age. Smoke tests seem to be the only real why to troubleshoot? Not by my experience but by talking to several service managers.
Might be a tool to look into cost of having to pay a dealer is getting so prohibitive while they troubleshoot such a time consuming system. Especially for those of us who try to keep vehicle longer. Alias tight wads
My daughter in-law has 2002 Caravan and I found a TSB where the Evap monitor program may be to sensitive. Dealer needs to reprogram PCM. For the .20 code which I believe is the smallest. New cap did not fix since the original physically came apart. Never seen that before. She was complaining the cap becoming harder and harder to remove so I lube the threaded area.
So now every few weeks I clear code while looking for possible other codes, check all the lines I can find. I see now why the dealers use smoke machines now.
It really be nice if the tubing was stainless steel,routing would be re-engineered, etc. and etc., if this system is so important that absolute integrity be maintained the bean counters need to comply, also? EH?
wonder what how the dealer tested? This wholesale changing out of parts ticks me off. Not cheap either.
I think our 98's only go down .40 not as sensitive as the newer stuff?
Paul

Good luck with yours!

Big Jim any idea how long this site been around and who behind it?
Looks like I need to do some investigating, 2006 Ford CD shows p0442 as the smallest as .40 not .20 as Chyrsler???
I was under the assumption OBD-II codes the evaporative would be all the same as "genertic"? Nothing simple anymore Yeesh!

TNX
Paul

Are you asking about this web site? The Contour Enthusiast Group?

I think F111D F is asking about this one. www.OBD-codes.com

Originally posted by Big Jim:
A loose gas cap most certainly can cause this code. Follow this link:

http://www.obd-codes.com/trouble_codes/generic/p0455-evaporative-emission-control-system-leak-detected-large.php
...

This explains why it was started.
http://www.obd-codes.com/about.php

Thanks guys! Tony me and my forgetter could use your mind reading abiltity! Or we think alike and that's scary for you. Hi Hi TNX

Paul

Originally posted by Tony2005:
I think F111D F is asking about this one. www.OBD-codes.com

Originally posted by Big Jim:
A loose gas cap most certainly can cause this code. Follow this link:

http://www.obd-codes.com/trouble_codes/generic/p0455-evaporative-emission-control-system-leak-detected-large.php
...

This explains why it was started.
http://www.obd-codes.com/about.php

That was posted so long ago that I had forgotten about it. I found it on a google search. Now that I look back on Tony's comments I realize that it is probably worth bookmarking for future reference. It looks like on of the better OBD II sites.