What is a DPFE?

 

Hi, I am new to this site. My problem is the transmission shifts every time you let off the gas pedal and put your foot back on the gas. It doesn't matter the speed or gear i am in. My check engine light is on also. My mechanic said to replace the egr valve, but it is clean. I have a 1997 ford f150 4x4 4.6 115,000miles. What do I need to do to fix this problem?

 

I had a similar problem, It was the throttle position sensor, it is like 25 dollars at autozone. The throttle position sensor tells the computer where the throttle is so it knows when to shift the transmission. It is very possible that you have a EGR underflow error as well, I fought with this repeatedly and finally resorted to tearing off the intake and cleaning it which resolved the egr underflow error. But for the shifting problem I would try the TPS first, it is real real easy it is right on the side of the throttle body on the top of the engine and you just have to unplug the connector and remove two phillps screws to get to it.

 

Hi Larry and welcome to the site

When the check engine light is on or has been on there will be a trouble code stored in the truck's PCM (powertrain control module or computer). The first step is to get it scanned and see what the code is. That should get you pointed in the right direction.
I think that tmulkey is on the right track.

 

Got my DPFE from NAPA for $50.00. I would like to say that that fixed the problem. It didn't!

I am gonna try cleaning the ports next.

 

Lately I've been having dreams of sitting in a different brand truck
and watching my P.O.S. '97 roll down a hill, in flames, heading towards
a deep lake. I wake up and smile. Oh well, only 2 years left to pay
it off. Maybe I'll have figured out why it won't start by then.

 

well looks like i get to do the same thing everybody else has to do
p0401 it is.


so to clean the EGR i understand i think, but do i really need new gaskets or can i get by with the ones i have if i don't break them/clean them/treat them nicely?


i'm a penny pincher

 

Clean the EGR ports, that is the important part. On the gasket,
if you can keep it from breaking, use it again. That can be very hard
to do, very delicate.

 

Thanks to everyone for the info. about cleaning out the egr ports. I was told by and "expert" at Autozone that my problem was the sensor, $51. When that did'nt work it "had" to be the egr valve, $50. That did'nt work either. I was getting ready to purchase a new egr solenoid when I decided to hop online first and see if I could get lucky.

Hopefully this trick will finally get rid of the 0401 trouble code.

By the way, the truck is a 98 f150 with 192,000 on what has been a trouble free 4.6L.

 

thanks to whoever brought this back to the top. I just got the P0401 code. I have the 4.2 V6 with just under 61k miles. so from what I read I should replace the DPFE. first of all I don't even know what a DPFE is, and will this one fit my truck? Ebay auction number 7980513777, the part number is F77Z-9J460-AB. is there a way I can check the old one to see if it's bad before buying a new one? I don't guess I have enough miles on it to think I oughta clean the ports, but I guess it couldn't hurt.
-thanks
-woogs

 

Hi ngerber40 and welcome to the forum

Please let us know if you get it cured.
woogs I would try applying vacuum to the EGR valve with the engine idling and see what happens. If the ports and valve are ok the engine will stall or almost stall and then it's safe to assume that the DPFE is the problem.
A F77Z number is from a 1997 truck. Ford has changed up the DPFE since then so I'd go to your dealer and buy the latest one.

 

to apply vacume, is that just pulling off the vacume line and covering the end? that wouldn't work it doesn't have any suction when it's just idling does it? how do I apply vacume?

 

Just take a piece of vacuum hose and plug one end onto the EGR and hook the other end to somewhere on the intake manifold where there is vacuum at an idle or just suck on the end of the hose.

 

well I went a researched it, it is the Differential Pressure Feedback System, The pressure sensor monitors upstream and downstream exhause backpressure. This backpressure coefficient is relayed to the PCM and the correct amount of EGR (duty cycle) is applied to the EGR Vacuum regulator control (EVR). By calculating the differences between the twp pressures, the PCM determines exactly the EGR flow rate at all driving conditions.

 

Has anyone else experienced this code due to the recent bad gas from union 76 in the western Washington state area? The local dealership charged Conoco-Philips 100 bucks to pour a can of injector cleaner in my s.o.'s truck, and then they said "they didnt get paid to turn the cel off". 02 ranger 47k miles, you think they wouldnt break while you were still making payments huh?

keep this thread up toward the top, its a big hit from google on DPFE, which has a LOT of problems that refineries didnt cause...