I don't know what the problem is im not getting a check engine light i don't know if the light even works when i turn on the truck it only displays the battery indicator, abs, 4x4, oil but i don't see a CEL. when i push the accelerator down hard its like its flooding the engine rocks and stutters bad idle or in gear and when in gear the truck won't speed up, if i throttle down slowly it functions like it should almost but when if i drive and do this i can get to about 30mph then it starts stuttering and stalling. before this started happening i had poor acceleration response and when i got to about 65mph the truck would shake a bit and sounded like lifters were rattleing and only when in gear and i would romp on it or going up hill. it would occasionally stall out and i would have to pull over and let it idle down then i could take off and get up to speed again but 2 fridays ago the truck stalled out and i couldn't get over 30mph anymore.
I changed out the TPS already someone suggested on these forums a few months ago and that didn't help. I just changed the Fuel Filter today some one suggested i do this on a different forum and it still remains the same. i donno the symptoms im experienceing seem like the ones from a bad map or dpfe sensor.

any suggestions?

 

Take it to autozone and see if there is any codes. It sounds like a bad plug, wire or coil but the codes should tell you.

 

yea i just went out and bought a diagnostic tool and i got a couple of codes p1401 (DPFE Sensor) and p1409(EGR Vacuum Regulator Solenoid)

going to replace those parts and pray that this solves my problem

 

I would start with the sensor and there are 2 differant ones plastic and metal make sure it is the same or it will not work I dought it is the Solenoid. If it is it will be the first one I have seen.

 

97 model years have the Aluminum Sensor - Right! needs to be replaced with the same one - There are 3 types used on these trucks in total (97-03)..

You sure about those codes ? What scanner did you go with ?

1400 series codes are valid, but they can be confused w/PO400 codes. Confirm that you are indeed receiving P1 vrs PO codes.

If your correct, heres a diagram that points out the components -



What's going on/ What needs to be checked -

Your PCM checks this circuit constantly while the DPFE Monitor is running and takes a four second sample.

The DPFE sensor is tested for out of range values (typically >4.96 volts, <0.195 volts) and if this is detected the DTC P1400 or P1401 is set.

The EVR Output circuit is checked for opens and short using the internal smart driver in the PCM, and a failure records P1409.

Check out the wireing , your connectors and such...

And yes, - could be a faulty DPFE. - That's pretty common..

BTW - This will NOT effect the way she runs. You have a different problem / an ignition problem. You need to go thru it if your not receiving codes. The plugs/wires/boots/coils....

 

You also need to check to see why you have no CEL. this could be an internal malfunction on the circuit board, also causing other problems

 

It's usually the cigarette lighter fuse. Same circuit that illuminates the CEL.

 

Nope. The CEL is NOT on the cigar lighter fuse, the OBD-II port is.

The CEL lamp is tested during power on. If it doesn't come on then, the bulb is likely blown. There are other causes, that's the most common.

A faulty DPFE sensor does have the capability of inducing drivability symptoms.

When it comes to replacement DPFE sensors, purchase your replacement at a Ford parts source. Otherwise, be prepared for continued problems. Aftermarket DPFE sensors seem to have recurring reports of problems of either very short lifespans or even out-of-box failures.

Steve

 

That's right! My bad - Thanks Steve.

I don't think so, - at-least that's the first I heard of it. How ? Well, -If the EGR system fails with the valve open, yes that's a drivability concern. - It will run like hell. If the system fails with the EGR valve closed there will be no driveability concern. With or without a MIL, the engine will run the same.

However, if the system is not gas-tight then air can be drawn into the inlet system instead of inert gas. This can weakens the mixture sufficiently to cause misfiring, and manifests itself as a noticeable misfire/hesitation at speed and light throttle, not present when accelerating. If the leak is serious enough it may manifest itself as a hunting/rolling idle, caused by an unmetered leak of air into the inlet.

BUT, none of that is due to the DPFE sensor. Unless your thinking about the hoses going to...

The PCM just checks the DPFE sensor voltage with a table in memory to check that the gas flow is within parameters. If the voltage is too high it indicates that there is insufficient gas flow, and this stores the DTCs. - Nothing to do with the poppet valve so she'll run like nothings going on.

 

I'll second that suggestion to stick with a Motorcraft DPFE sensor.
Also, if your truck has the aluminum-bodied sensor (our '98 still did...same as on my '97), the new replacement from Ford will be the updated plastic-body version. It works just fine except if this is a 4.6L the hoses might be just a hair too short to reach the ports without kinking them.
I replaced the hoses at the same time I did the DPFE since the rubber was starting to flake off anyway...the little flakes of rubber were what clogged up my original DPFE sensor.


If the CEL light doesn't come on with the lamp test when you turn the key it's likely that the bulb is burned out...or the previous owner just pulled the bulb

 

I replaced my DPFE with one from the Ford dealer. The parts guy asked for the vin # and checked to make sure it was the updated match for my truck. It's gotta be the right one!

 

yea the light test doesn't show the CEL light and the cigarrette lighter works i use both ports for my sirius radio and for other stuff. and pending codes do not trigger the CEL light.
as for the solenoid when shut down the engine i hear strange nosies commin from it i donno if it normal makes a weird noise when it shuts down
im using a innova 1003 OBD2 Diagnostic tool i bought from sears and im sure that the codes are correct
it tells you what the problems are with the code on the scan tool it self

 

Then you just learned something new.

A DPFE sensor that is mis-reporting the rate of EGR flow will cause the PCM to mis-command additional flow leading to drivability symptoms.

Note that the most typical DPFE failures are when they simply die. However, that doesn't cover all failures.

That's pretty normal. It's just the manifold vacuum bleeding off through the EVR solenoid and the diaphragm inside the solenoid is vibrating like a reed in a music wind instrument.

Steve