CHECK ENGINE LIGHT???

[97splorer]

MY CEL HAS BEEN ON MY X SINCE ABOUT ONE MONTH AFTER I BOUGHT IT(NOVEMBER OF 2001). WHEN I HAD IT CHECKED THE MECHANIC TOLD ME THAT THE CODE WAS IN THE MEMORY FOR THE EGR VALVE, BUT THE VALVE WAS GOOD. AFTER RESETTING THE COMPUTER IT WENT OFF BUT CAME BACK ON ABOUT TWO DAYS LATER. WELL, IT'S BEEN ABOUT A YEAR AND A HALF IT RUNS FINE AS FAR AS I CAN TELL AND ALWAYS HAS. WHAT DO YOU THINK THE PROBLEM COULD BE? i HAVE ABOUT 83,000 MILES ON IT. I HAVE A SLIGHT EXHAUST LEAK WOULD IT CAUSE THAT? ANY HELP WOULD BE GREAT
THANKS.

 

[Robb]

Do you remember exactly what code it through?

Robb

btw: Please don't use all caps on the forums

 

[97splorer]

I belive it was DTC-p0402 the paperwork also saysF48E-9J460-BB does that help? sorry about the lettering.

 

[Robb]

I will throw this out and see if other members agree with me. I have never gotten a p0402, but I have gotten two p0401s on different Fords (which came up as something about the EGR). Both turned out to be the DPFE. I believe this is a fairly common problem.

Let's see if others agree with this,

Robb

 

[410Fortune]

The light has been on for a year and a half?

Or the light came on again after a year and a half?

If it just came back on you may want to scan the codes again, it may be un unrelated problem.
If you have a CEL then you need to start with the trouble codes it is on for. They are in order, most promenet code first, and some of the later codes may be caused by the real problem.
Most of the time the computer does not lie.
If you get an EGR code and the EGR valve is new, clean, and sending the proper signal to the computer (can be checked) then the problem lies elsewhere, in the wiring to the EGR valve, a loose connection, etc.....

So Ford telling you the EGR is fine but the CEL is "just on" and "we dont know why the EGR is okay but the light is on" is not okay. They should know why its on and dig deeper into it......

 

[97splorer]

well the light HAS been on for about a year and a half, the mechanic said that it was a memory code or that the EGR valve may have been bad and replaced before I bought the car and the code was coming out of the memory. My X has always run fineand I have never had any issues with it (nock on wood) so how worried should I be?

 

[MrShorty]

If I understand correctly, here's how the system works. When the computer detects a fault in one of the systems it monitors, the CEL comes on. If the fault is later corrected or corrects itself, the CEL will turn itself off, but store the fault code(s) for later retrieval. If the fault doesn't return after a certain number of start/stop cycles, then it will clear the code.
Point is, if the CEL is still on, then the computer is still seeing some kind of fault that should probably be investigated.

 

[97splorer]

thanks, I'll go get it checked out

 

[fordkrazy]

its the pressure feedback sensor for the EGR if the valve is fine

that is the position sensor for the EGR valve....if the code is for the EGR valve itself and it is fine (have you visually inspected it off the vehicle?) then the hoses to the PFE needs to be replaced or maybe the sensor itself. you really need to know which code it is to make an accurate decision.

 

[97splorer]

I'm not too experienced under the hood, I'm not sure where the EGR valve is. is there anywhere to find a diagram of it so I can see for myself?

 

[fordkrazy]

get a repair manual....it will show you where it is

if you get it off and it looks cruded up then its bad....i doubt its the valve....it should also move fairly easy since it operates on vacume..if it takes a lot of pressure to move it then replace it (it will be stiff though cause its spring loaded to the closed position)

i would say as new as it is that its the pressure feedback sensor (PFE) or the rubber tubes going to it are clogged but generaly clogged tubes wont throw a code...just make it run weird

 

[camaro350]

I have kinda the same thing happing to my ex. The CEL comes on and off. I ran a scan on the codes and got a low voltage EGR reading. Has anyone seen that one before. The cel will usally come on when i'm going over 50 mph. It will stay on only for a few minutes. :redexp:

 

[fordkrazy]

that sounds like clogged or cracked DPFE tubes....i would replace them

 

[V8-X]

I too would recommend testing or replacing the PFE or DPFE, which ever your engine may have. Don't have my manual with me at the moment. As stated before, also check the rubber tubes connecting to the PFE/DPFE. I have seen a lot of post regarding the PFE/DPFE & tubes getting clogged by carbon build up. If the PFE/DPFE is not functioning properly, this will throw off the EGR. Which in turn will trip your CEL. Hope this helps!

 

[Positive Vibes]

Where would you get the vacuum hoses to replace them? I have tried the dealer, of course they don't sell them. All the wrecking yards here are X free (none) so that's not an option. I have the same symptons as camaro350. I have fuel/oil in my vacuum lines. I have replaced the Fuel preassure reguelator and the PFC valve. I got a EGR from the dealer but of course it was the wrong one and I didn't notice till I had pulled the original out. I need to clean the MAF but cant locate the special alchol and a security torx bit. Stupid Ca!

 

[camaro350]

I called the dealer and they do have the vacum line for 8 bucks a piece. I looked at mine today and the rubber pieces look worn and weathered. I will let you know how it goes when I get this done.

 

[Positive Vibes]

camaro350: Cool. Could you get me a part # please. I ended up blowing out the lines and adding new end connectors but I would rather have clean vacuum lines. I swear California has more rules than Singapore.

 

[fordkrazy]

positive vibes...you can use fuel line tubing.....they are different sizes though...just take the hoses to an auto store and they will get you fixed up....if that doesnt help then you need a new DPFE or the EGR vacume control solinoid....the only way to tell which one you need is by the code you get...if it is one telling the EGR signal is out of range then you need to replace the DPFE...other wise you need the vacume control solinoid.

the way the DPFE works is by sensing the ammount of gases going through the sensor....the more the EGR valve is open the less gases will flow through the sensor...its like electricity..the gases flow through the path with least resistance.

 

[Positive Vibes]

fordkrazy: Thanks for the info! I don't recall seeing a DPFE on the diagram in Chiltons. Is that the same as the vacuum solinoid you were refering to?
"EGR signal is out of range then you need to replace the DPFE...other wise you need the vacume control solinoid. "

Anymore info would be great. I've been trouble shooting this for a couple of months. I just don't want to have to take it in. I'm learning a lot by trouble shooting this problem myself ( and the help of the fantastic people on the board).

 

[fordkrazy]

yea the DPFE is differant than the vacume control solinoid....the VCS is what accually opens and closes the EGR valve and the DPFE is what senses the amount the EGR is open by diferantial pressure

the DPFE is the silverish rectangular thing right below the IAC (thats what the rubber tubes go to from the EGR pipe) and the VCS is to the right of it and its black(if you trace the green vacume line it goes to the VCS)

i dont know that you really need an EGR valve since they are pretty durable now days....what codes are you getting?

oh yea...be sure to use only chloride free brake cleaner when you clean the MAS...do NOT use carb cleaner or alchahol as these leave behind deposits that make it dirtier than it was before...as for the security torx bits....i found a set at O'reily's