95 Bronco 5.8 idle problems - new code 332

That may but should not have caused an idle problem other than a distrubance of the air flow around the MAF sensor. The ECM does not use the ACT sensor to determine idle speed requirement.

You are usually looking for a bad electrical connection, a vacuum leak or a bad EVP sensor which is located on top of the EGR valve. The EVP sensor is what tell the ECM how far open the EGR valve actually is. The system has no other way to measure EGR flow. If you had an analog VOM, pin the wires at the connector to find which is the one with variable impedance. You find one with ~5vdc (your 4.9vdc is good). Voltage in the circuit is controlled by the ECM at

4.75-5.0vdc. If you remove the sensor from the valve, you will see a plunger at the bottom. As it moves, the resistance and output voltage should change very smoothly with no glitches on your VOM to cause any noticeable nonlinear movement of the needle. Be sure to check your vacuum connections and lines to the cannister on the fender and the lines around the rear of the intake manifold.

Lugnut

Hello Lugnut.

My EGR doesn't have the EVP on top of it. I know, every photo and reference to the two show the EVP on top of the EGR. I suppose mine is different because of the California emissions setup. What I'm assuming is the EVP, is rectangular (about 3x2 inches and 3/4 in thick) and has what looks like 2 vacuum lines running to two metal tubes that are connected in two different places to the metal post the EGR sits on. The EGR sits on the post alone with one vacuum tube connected.

I was wondering if I should take the EGR off, and maybe clean it, or see if it is functioning somehow. Of maybe someone might recognize this specific problem. Maybe it's the EVP? Would this problem cause the idle glitch?

Thanks, John

that little sqare box with 2 hoses going to it measures differential feedback pressure (dpfe sensor) flow to egr valve. seen any fords running bad and getting an egr flow code with dpfe sensor bad i usually remove the hoses at the ex pipe and see if both hold a vacume into the dpfe .ahole in the hose or if the hoses are loose can cause code , or a diaphram in the dpfe could be leaking.

As the previous poster mentioned, what you have is a DPFE -- differential pressure sensor. It measures the flow indirectly, by sensing the pressure drop across a restriction in the EGR tube. The DPFEs of that era are prone to failure; they get 'stuck' at some constant reading, typically at the end of the range. It's fairly easy to test the device with a vacuum pump and a DVM, but as they are relatively inexpensive (probably around $35 for an aftermarket part), it may be simpler to replace rather than take the effort to test. Make sure the tubes are intact and connected properly, and don't switch them around...

Yes, thank you. I have a DPFE. I'm still wondering about the idle glitch. Do you have any insight there?

thank you for pointing that out to me. big help.

What you are describing is a DPFE sensor. They are commonly responsible for this code - usually not the EGR valve itself. The DPFE has been a problem across the Ford line whereever it has been used - especially those before the

2001 year models. The first thing I would do is make sure the lines to/from the DPFE are both open and not leaking. They tend to collect both moisture and carbon from the exhaust. The DPFE sensor is easy to change and cheap.

Lugnut

Have you, or anyone else, replaced a DPFE sensor? If so, I have a question

Not on that particular engine. I have on others. Usually, the only problems is getting your hands on it. On the 5.8L, that should be relatively easy if it is like other small block Ford service items. What is your question? The answer may be generic in nature. I'm sure someone here has an answer.

Lugnut

Do you remember if the part came with the rubber hoses? The parts store only had one, and it was just the metal part, no hoses.

Alll I have ecer seen are bare sensors. The only time I have seen anything other is if it is part of a recall campaign and other parts are required. One of more of the tubes may have to be sourced from the dealer or fabricated if it is not reuseable.

Lugnut

OK, thanks. The tubes/hoses on mine look permanent to me, as far as the sensor to hose connection is concerned. I didn't want to start yanking on them without asking someone. Gracias.

I got the DPFE sensor on fairly easily. The cheapest one I could find was $40. The CEL light still comes on sometimes, but the idle problems seems to have gone away. I swear it has something to do with weather (temp/humidity). Next, I'll take off the EGR and try to clean it.

On cleaning to EGR, do I spray it down good with carb cleaner, like an IACV? Would that damage the diaphram at all?

John

That is probably the safest thing to do. If the tubes are plugged, you may have to use a piece of wire to clean them. I would not probe too deeply into the valve itself as it has a diaphragm in it. An EGR that is too far open can cause high/bad idle. This can be a result of a bad DPFE. The biggest problem tubes for EGR operation are those to/from the DPFE itself. The Exhaust tubes to the valve are not usually a problem unless you have an oil burner or it is running excessive fuel for a while.

Lugnut