since everyone is so knowledgeable, i have a tricky question-or so it is for me... my 2001 ranger has been acting up. as i'm coasting into a stop sign at roughly 30mph, my rpms will drop, then all the needles on my dashboard drop, and my headlights dim, but as i continue to coast, they'll usually flicker back on, but on occasion wont, and i'll need to throw her in neutral and start her up again. in a town with quite a few stop lights, it gets quite annoying as it will happen at each light-any ideas??

Engine size?

Check engine light?

Do you ever have problems starting or running rough after a cold start?

My intitial thoughts are IAC - idle air control, MAF - mass air flow, EGR - exhaust gas recirculation, Vacuum Leak.

knowing the engine size will help narrow down some possibilities.

So did you get the truck in to take a look at it yet?

It kinda sounds like a IAC to me too...
But without scaning it you won't know for sure.

I would sya its a DPFE sensor

sorry for such a late update-i finally got it scanned. i have a buddy that works at a parts store and was able to get it scanned-it came up as an O2 sensor or an egr sensor... i replace the O2 sensor and it hasn't solve the probelm.. should i move to the egr sensor?

D.P.F.E. sensor is cheap. $20-$30 bucks. The D.P.F.E. sensor is the E.G.R. sensor.. I would start with this next. Replace the part, clear the codes with scanner or disconnection negative battery term. for about ten minutes and then drive as normal.

The D.P.F.E. sensor is not hard to do..



Good luck..

well i just changed the egr valve-didn't solve the problem either... it was $60, and really easy to do, but didn't solve the problem... is the EGR, or DPFE SENSOR different from the valve?

Yes they are different parts. The DPFE sensor is what measures the amount of exhaust gas that the EGR is allowing to enter the intake. Typically this sensor is stuck at a particular voltage, When the EGR valve is opened the signal from the DPFE does not change. The computer sees this and flags a check engine light. Most of the DPFE sensors I see are stuck high wich makes the computer think that the EGR is open. They can also be stuck low wich can fool the PCM into thinking the EGR is not opening.

I will usually scan these and find out what the code is. If I see this code I go to the data on the scan tool and see what the DPFE sensor is at. If high I know the sensor is bad. If low I will start the vehicle and apply vacuum to the EGR valve and see if the voltage changes. This does two things, one is I expect that the fully open EGR will try to stall the engine which it should do, the other is that I should see a rise in voltage from the DPFE sensor. If the engine does not try to stall than I will focus on either the EGR valve or the more common plugged EGR passages which are common on the 4.6 and 2.5 ford V-6's.

well my check engine is on sometimes, and off sometimes... it was off today. i'll hafta go back and get it scanned again and check the DPFE sensor voltage. how would i be able to clear out the passages?

They don't necessarily have to cleaned. Thats why you apply vacuum to the EGR valve. If the engine begins to run ruff or stall it is doing what it suppose to do. If the engine does not run ruff/stall then I would worry about the passages. The engines available for that year 2.3, 2.5, 3.0 and 4.0 typically do not have issues with plugged passages like the 4.6 and 2.5 do.

What Airjer said!

Here is the dpfe senson

well after replacing the egr sensor, and then cleaning the mass air flow sensor, non of which worked, i'm ready to give up and bring'er in... and last suggestions?

How many miles does the truck have on it?

Clogged E.G.R ports would be my last shot????????

How many O-2's did you replace?

I would get it scanned again and see what codes pop up, one last time.

Could be a bad "new" part?????????????????

Good luck.