I'm no expert, but if the code is the evap system, it could be as simple as a gas cap that doesn't seal and hold a vacuum.
It may also have something to do with the purge valve to the charcoal canister. The one on my Ranger bit it last year and threw an evap code. Repair parts were a whole kit with hoses for the Ranger, not terribly expensive from what I remember.
This code has to do with a control system pressure sensor being out of range or reacting too slow or too fast. l do not have my manual handy to tell you what to troubleshoot. But I would not start randomly replacing hoses and caps. You could end up masking or causing other problems.
Last edited by wildcard30; 07-04-2007 at 02:50 PM.
A guy that I work with was getting that same code on his 04 xlt 4.6.In his case he said it was a bad fuel tank pressure sensor.I don't recall if it was located on top of the tank or in the tank but they had to drop the tank to get to it.
In your case it may not be the same problem he had but it may be something worth looking into where your getting the same code.
Are you having a specific problem? Is the truck running poorly? And if you are having problems, when are they happening? Truck cold, truck hot, after filling gas tank, when idling?
Give us some more info please.
Spend a few dollars on a good shop manual. You can "replace parts" from now until Christmas and not find the bad sensor. You will eventually find the bad part, but you may end up replacing most of your emissions sensors in the process.
It would suck if you replaced $100.00 in parts and not get it fixed. But if you were to spend 20 bucks on a manual, it would help you troubleshoot it down to the correct part.
So it could be as Nassty says. Or you could have bad wiring, causing noise on the circuit, even a tank venting problem. Do you overfill the tank so there is fuel in the neck?
Here's some info I found on another site... (edit: The following info is from the Ford OBD manual)
The Fuel Tank Pressure Sensor input circuit is checked for out of range values (P0452 short, P0453 open), noisy readings (P0454 noisy) and an offset (P0451 offset).
The offset test is new for the 2004 MY.
Note that carryover 2004 MY software and 2003 MY and earlier software will set P0451 for the noisy sensor test. Note that an open power input circuit or stuck check valve generates a P1450.
Let us know what the truck is doing....
Last edited by wildcard30; 07-08-2007 at 12:37 PM.
Wildcard you will be surprise to what made the check engone light go out. I waited to my tank was about empty and I bought a gas treatment by Vavleline that cleans emission and then went and put some gas in the truck. One day later after the treatment went through the light went out. Wow. Thanks