PO457 Again. WTF! 2002 sport trac "check fuel cap" and CEL illuminated.

[Joey P]

Searched and found 2 threads pertaining to this and one of them is my thread. Neither explain how to fix this. One of them says to "hunt down the vacumn leak" but it's not too specific to where to look for it and the Original poster never posted back about if he fixed it. My thread I replaced the gas cap in this thread and it fixed the problem..... for a short while. Code po457 came back and I bought a new gas cap and PO457 came back after the new cap. I took the gas cap back to the auto parts store and they gave me a new gas cap as we thought the old one was faulty. PO457 came back. I can reset the code and CEL with the code reader I have and within 3-4 days the code PO457 comes around and pisses me off. The Check fuel cap light comes on first by itself and then within 1 day after the the CEL come on.

Ok, so not the gas cap, right? And

What the hell do I need to do here?

 

[thunderhorse]

After cap I'd start running down vacuum lines in the evap system. good luck and let us know how it goes.

 

[Joey P]

OK. I'm not familiar with the evap system. Where do I start? How many vacuum lines are we potentially talking? Could I lean more towards the rear of the vehicle because of the check fuel cap light?

 

[DBray6]

The evap lines are pretty easy to chase. Drop the spare and look for the hoses coming from the fuel tank and by the filler tube. I found that the tube that connects the two charcoal canisters was routed under the support instead of over the support when I went looking around. Everything is easy to see and pretty easy to reach. I did get VERY dirty. The hoses that go to the front are steel until they reach the engine compartment.

 

[Joey P]

Alright. I traced all the evap lines I could find. No cracks loose lines or anything. I've been living with the light up until today. I washed the trac today at the car wash. I Sprayed high pressure water up in the direction of the charcoal canister(?) and proceded on my way and then I noticed the CEL and Check fuel cap light was off! I checked codes when I got home and there is no more PO457. So I'm even more confused. Any idea why washing the area of the charcoal canister would clear the lights and codes?

 

[Project_Sparta]

Maybe its magic water?

j/k, thats weird, maybe there is a loose wire on the sensor?? my best guess.

 

[mbautodesign]

i got that code on my truck last week too
i erased it with my scanner and it has yet to come back on

 

[Joey P]

It's been almost 2 days and still no lights or codes. This has been an ongoing issue since I've had the truck. Until I find it, I'll be going to that same car wash!

 

[mbautodesign]

well the week after that CEL i got the 2-3 shift flare so hopefully you dont have my luck!

 

[Joey P]

HA! I've already got that!

 

[mbautodesign]

how long have you had it?
what do you plan to do about it? (ford tsb parts, rebuild, etc)
i am actually hoping to trade it in and hope they dont notice it when they drive it, it only happens now and then.

 

[Joey P]

I'm planning. Planning. Planning. Planning on doing a 5 speed swap. Mine isn't that bad and only does it now and again. But I'd rather have a 5 speed vs. and auto.

 

[Gincophie]

So, was there any final amazing solution on this? I had the Gas Cap light come on. Now got the P0455/P0457. Will try new gas cap and then magic water....

 

[And]

I did my studies with ford, during that time my teacher said that some canisters accumulate dirt, and mess with the flow of air going out or in, cause all kind of problems, washing it might have done the trick.. but maybe not..

 

[1.8TTony]

No reply yet......

FTP sensor on top of fuel tank.
Bad fuel pump ring seal.
Bad/dirty electrical connector on FTP sensor
Cracked/leaky vapor return port on top of fuel pump module.

 

[koda2000]

If you live in the salt-belt, it has been reported that the steel filler where it connects to the rubber filler hose is subject to rusting through where the hose connected. This happens because of the angle of the filler hose and neck. Water/salt sits/soaks into on this joint and eventually can rust out the steel filler neck. I imagine the vent hose is subject to the same rust. You should check these areas.

The PCM has know way of knowing where a vacuum leak in the fuel system is (if in fact there is a vacuum leak) it just knows/thinks that there is a leak and a very common place for this can occur is if your fuel cap is missing, has a damaged gasket, or not fully tightened. There are numerous places that vacuum leaks can happen. The best way to isolate a vacuum leak is by having a smoke test done.