Contour Enthusiasts Group Archives Forums General Troubleshooting DPFE Sensor - Conversion 1995 Contour

Hi! The '95 Contours are OBDI, and the original DPFE sensor is metal. There is a replacement part that is plastic and requires a wiring conversion. Is this a successful conversion? I would think so because Ford sells the part (and we've confirmed the number's correct for my car) but we've replaced it and we're stumped and can't get the CEL to go off. According to my husband's resources, the reference voltage from the sensor to the PCM is different. Anyway... here's what we've done so far...

First, the car has and continues to run and idle fine, but some time ago the CEL light began going on and off, cycling on more and more often. We checked codes and got 332, the EGR valve wasn't opening properly. Since I have 63,000 miles on the car, we went ahead and put in a new EGR valve & gasket, and EVR solenoid - pretty inexpensive parts. But, after clearing codes, CEL still came on intermittently and showed the 332 code.

So... next we took the throttle body off the intake manifold and cleaned it thoroughly (and gently with teflon-safe cleaner and a soft toothbrush). We also cleaned the ports behind the throttle body and replaced the old gasket with sensor safe-silicone sealer added. Runs fine. After cleaning the throttle body (very gunked up) the car started and ran smoothly. Cleared codes/removed specified fuses for specified time, but CEL still coming on.

At this point we replaced the DPFE sensor. To do this, per Ford instructions, we had to modify wiring, cutting the harness and using a pigtail; also the new DPFE is plastic instead of metal. We confirmed part number. We followed instructions carefully so we're very sure installation was correct. But, after clearing codes/pulling fuses, CEL still coming on. But now it's constant (or maybe it became constant after the throttle body cleaning; anyway, it now comes on after beginning to drive and pretty much stays on).

So we checked all related hoses; and checked vacuum pressure, which is fine. The EGR valve seems to be working; when we pull a vacuum on the EGR valve the engine stalls on idle, meaning the valve is doing what it is supposed to do. And the EVR solenoid on acceleration pulls vacuum on a gauge, indicating it is working, too. We checked all related hoses; and checked vacuum, which appears to be fine. We also cleaned the tube running from the EGR valve to the exhaust system. Car is still running fine, idle's still in the right place (always has been; around 750 rpm, but cycles up above 1000 rpm while air conditioner is on, which I think it's always done). SIGH... CEL is STILL almost constantly on, coming on soon into driving.

Have others here done the plastic DPFE conversion on a '95 model Ford or Mystique and had success? We've come to find out the original metal DPFE is still available, and are wondering about this voltage difference possibly being the problem. Any other ideas on how to proceed?

Thanks very much!! Lynn
Ford Contour SE MTX (V-6), 63K, electric red
(Ferret II)

I believe all DPFE units have the same output.

You will want to first verify that the EVR is working. The EVR provides vacuum to the EGR valve.

Put a vacuum pump on the intake side port of the DPFE and use a meter to verify the following KOEO :


Pressure ---- Voltage
---0 PSI --- .45 volts
-.50 PSI --- .90 volts
1.00 PSI --- 1.40 volts
1.50 PSI --- 1.90 volts
2.00 PSI --- 2.40 volts
2.50 PSI --- 2.80 volts
3.00 PSI --- 3.30 volts
3.50 PSI --- 3.80 volts
4.00 PSI --- 4.25 volts
4.50 PSI --- 4.60 volts

The table is pressure across the ports, so since the exhaust manifold port is at one atmosphere use twice the inches of mercury on the intake side port.

Did you clean the EGR port area like this?

http://www.contour.org/ubbthreads/showthreaded.php?Cat=&Board=v6maint&Number=337774&fpart=&PHPSESSID=


The dealer did this on my sister's Duratec Mystique, also a 1995. Cost a bit, but could be done at home next time. Cleaning stopped the code.

Hi. Thank you to those who wrote me about this. It had turned into a real head scratcher!! But is solved. The plastic DPFE sensor works fine, although the only reason we could find on the web for converting from metal to plastic was some kind of interference with radio reception! The metal DPFE for the '95 Contours is still available and we found one on the web for about $60, and Bill Jenkins also has it at a reduced price, so I'd advise going with that if you can, as you don't have to cut and re-soder wires.

Here's what the deal was. The vacuum tube size for the intake and output ports is switched in the plastic DPFE, but there is no indication of this in the otherwise very
detailed and thorough Ford installation/conversion directions. Janos found a picture of the plastic DPFE system on a Ford Scorpio website (same system) and noticed the change. So... he switched the hoses and voila! CEL light went off (without clearing the codes)!! What a relief. The DPFE worked okay with the hoses wrongly installed, car drove fine, but the voltage is slightly different between the two ports, creating wrong info to the computer. We also had to buy a longer silicone hose for the wider-diameter port; by American measurements got a 7/32"", and it has to be at least a foot long; ours was just an inch short and Janos says need will depend on the original hose's length; someone else's car might already have a longer hose.

Now... just have to get the dang-blasted coolant sensor light off again. We'd found the sweet spot for coolant level but got the coolant system flushed and haven't been able to hit the spot again. Minor, minor issue. Car is running nice and cool.

Should have cleaned out that throttle body long ago as Big Jim advised me!!!! Not doing so could have led to this whole issue. Just never got around to it and Janos was worried about the "don't clean the teflon" Ford structions... but the teflon just means it can go longer; it still needs regular cleaning at some point! I think Big J. also mentioned cleaning the IAC so will go look at some of my old messages and make sure we do that if it's advised. He also adivsed Redline fuel injector cleaner, but I can't find that and the guy at NAPA who has had 35+ cars talked me into Lucas brand, which he says, of trying multiple kinds, is his favorite. Big Jim rules!! So does Bill Jenkins, who for many years has made us great deals on parts, and has the patience to answer my questions, and the rest of you CEG guys.

Thank you all again! Here I am keeping my beloved '95 SE low mileage and at some point I worry that the support for it will move on... such a fun little car.

Lynn
Ferret II - '95 Contour SE (V-6) MTX, 63K, electric red

You fixed the original problem, and got a free "bonus" problem. That happens sometimes. I am glad you fixed it, in spite of bad instructions! I printed your solution, because it will be needed if I ever install the plastic DPFE on my sister's car. I might just get the metal one!