CEL went out on its own, why?

[demarpaint]

Originally Posted By: Vikas
See if the the code is still pending. I do hope that you finally purchased the scanner otherwise dealer *will* take you for a ride.

- Vikas


You convinced me. I bit the bullet and ordered one this morning. Pointless not having one. A buddy told me that over filling the gas tank can trigger a CEL in very sensitive systems. My CEL came on long after I gassed up though, this past time I had 3/4 of a tank remaining when it came on and about 50 or so miles later it went out. I'm new to this but quite familiar with the Ford systems from 93 and back. LOL.

I will make sure when I fill up that I don't round up from lets say $24.07 to $25.00. I'll round up to $24.10 in that example. Once I have my hands on the code reader I'll check it again and then decide if I should bring it in or not.

Again thanks for all the help!

 

[Vikas]

If you use plastic at the gas station, STOP at the first click. If you do use real cash, still try to stop at the first click. Let the gas station give you all your pennies back.

Which scanner did you order? If it gives you Mode 6 data, you can find lot more information which will tell you which test was on borderline.

- Vikas

 

[mechtech2]

demarpaint - What you CAN do is check all vacuum lines and connections - loose, kinked, whatever. Same for any electrical connections. Nose around the EVAP valve and charcoal canister.
Peruse the lines from the gas tank.

 

[demarpaint]

Thanks for the tips guys. I remember a while back taking the spare tire down to clean it and put air in it, shortly after the CEL came on, maybe I upset something back there? Funny when you read thru these threads how it gets you thinking. I will also stop the pump at the first click. Driving old cars all these years you take a lot for granted.

Vikas I ordered the Eguus 3160 scanner, under $215 to the door.

 

[Jimmy9190]

I had a P0441 code and CEL come on my Dakota. I know it's probably different form your Ford but in the process of fixing it I learned it is bad to "top off" the tank when filling up because the excess gas vapor eventually ruins the charcoal in the evap canister. I never topped off my fuel anyway, but that was something I did not know before. A bad evap canister is just one of the 8 or 9 reasons you can have a P04-- code. I also read that if the gas cap is bad, you are more likely to get a P0442 code. That may not apply to Fords either.

Mechtech is right, you have to check all the emissions lines and hoses very carefully. The fuel vapor deteriorates them from the inside out. The ends get split and cracked from heat, cold and old age.

In my case, I fixed one cracked hose end and put on a new gas cap, had AAP clear the code and P0441 came back 2 days later. I was in a wreck recently and the accident also broke my battery tray. The body shop replaced the battery tray, but I reasoned an impact hard enough to break the battery tray probably broke my Leak Detection pump too, since it is mounted to the bottom back side of the battery tray. A new LDP is $130.00 at the dealer, and I did not want to spend that much and have it not fix the problem. So I replaced all but one of the emissions hoses in my engine compartment with $7.00 worth of fuel line hose, and I replaced my LDP with a $20.00 used one from a "Cash for Clunkers" truck at a junk yard, and did a hard reset on my PCM. The one hose I left alone is a dealer only part and is a formed hose that is probably very expensive, plus it is in great shape so I left it alone. I checked all the emissions lines at close range with a bright shop light looking for splits and cracks.

That was 10 days and nearly 500 miles ago and my CEL has yet to come back on. I hope I am not jinxing myself with this post. But Mechtech is right, you have to check everything very thoroughly and replace what you can in a logical order. Sooner or later you will know what's wrong.