Check engine light still on
 

Ok I went to Auto Zone and had them run a scan through my truck-99 ford ranger, V-6, standard. the little gadget reported one problem it was the EGR valve so I spent the $55.00 to purchase the part and 1st timer on anything auto, I replaced it myself it was simple just 2 bolts and the attachment which looks like a hose or something but anyway its been replaced but the light is still on.. what gives? I ran the truck all day and it runs smooth. Could something else just went bad as soon as I replaced the reported problem?

Does the bottom attachment to the EGR valve supposed to stay dry and nothing inside of it?

I'm assuming you replaced the DPFE sensor...?

Did you erase the trouble code after you did that? You can reset the computer and erase the codes by taking the negative battery cable off the battery for about 20-30 minutes...

I sounds like you replaced the EGR valve. Do you remember the
code you had? If it was P0401 "Insufficient EGR flow", the problem is probably the DPFE sensor, not the EGR valve. Joe is correct on resetting the error codes in the PCM......

Numbers crossed-po401

Troublecode OBD11 (ALPHA) P Code

TROUBLESHOOTING PO401

The PCN has determeined that there is Insufficient flow in the exahust gas recirculation system.

That is what I have. So it is not the EGR Valve? What is DPFE sensor?

Where is that located? can someone like me who has no mechanical skills replace it themselves and how much is that part?

Try doing a search on it. I seem to recall someone posting a pic showing it not too long ago. My rig doesn't use one but from what I've read about it, it's fairly straightforward to replace.

On edit: Do remember to clear the code(s) when you're done, as described earlier.

It is mounted on the upper intake, facing the front of the truck. It is rectangular shaped, has 2 hoses running into the bottom of it and an electrical plug into the front. I bought one a few months ago from Ford and it was $74. The original was aluminum, but the replacement was black plastic.

AutoZone does carry the DPFE (Differential Pressure Feedback EGR ). But, if you ask for a DPFE sensor, they have no clue what it is. I just did the same thing to my 98 Ranger. Replaced the EGR valve, still had engine light. I replace the DPFE sensor and it worked (so far). The one from AutoZone is also cast aluminum (not plastic) and it is around $50 with two vacuum hoses at bottom and a 3 wire plug on top. Looks a little larger than a Zippo lighter. I believe on their computers, they only pull up two things in the EGR system of a Ranger: 1) the actual EGR vavle, and 2) the EGR Pressure Valve sensor (FORD'S DPFE). Hope this helps!

I think the reason Ford went to the plastic DPFE sensor is due to a corrosion problem with the aluminum design....Just my $0.02

I've often heard that reason given too Bob and I think it makes the most sense.

Another possible reason for the switch from metal to plastic that I've read about, and that I also have questions about, has to do with radio interference issues.

How about that?...do you think an aluminum DPFE could in any way cause radio interference problems? As you know already Bob, that kind of automobile electrical stuff isn't really my strong suit (but I am getting better at it, yes indeed)..:D

Yes Joe, IMHO, you are a tremendous technical asset to FTE!!! You are also too modest!!!!!

In looking at the schematics for the DPFE sensor, it is fed +5V from the PCM, and the differential in pressure changes the voltage drop between ground and +5V. (like a potentiometer).
There could be a slight arcing when the potentiometer is changing values with the aluminum DPFE sensor....just a guess, but the arcing could cause RF interference...

so I replaced the EGR valve and disconnected the negitive cable from the batt as suggested I do, the "check engine" light was off, but sure enough it came back on. So now its the DPFE sensor? is this exactly what it is called? I dont want to ask for that and have the auto zone guy look at me like im from another planet.

Would this be in my face after I pop open the hood? is this hard to fix?. I have a mechanic that works where I work and he repairs companies vehicals he said my truck has 3 parts that make that check engine light come on-one is the EGR valve sytem, DPFE sensor and what is the other?

does someone have a up close pic of the part in the truck?

On my 3.0 its mounted to the front of the upper intake manifold, two screws, two vacuum hoses and an electrical connector.

Something to keep in mind ...the DPFE is often referred to as an "EGR Pressure Sensor", or something similar to that, at the parts stores.

I am experiencing the same exact problem with my 99 Ranger 4x4 SC. I went to Autozone about six months ago and they told the same as what they told you. I also replaced the EGR valve, reset the computer only to have the light come back in two days. I went back to Autozone and had a different sales rep run the check again with the same results, only this guy said try running some good high octane and octane boost/cleaner through a couple of times and reset again. I did this a couple of days ago and reset the computer today, so far so good. I will let you know in a couple of days if my luck holds out. I have heard about this before, bad gas causing the idiot light to cause eye strain that is.

Thanks for all your good advise.

BC

Same story with my Ranger Do like me....Put the For Sale sign in the back Window and be done with it....LOL I lvoe the trucks..but NOT mine...Try to O2 sensors...EGR valve could try the computer for a loop on those..

Ryan