EGR failure...can i just take it off??

ninety15.0 · Apr 6, 2004

So i pulled codes on my car last night because it was running like crap and i would bog like crazy at like 3k rpm and up. the fuel pump was a lot louder than normal so i thought it was that. When i pulled codes i get codes for the fuel pump relay failure....and for EGR failure, and for right side 02 sensor failure. I think the last two may be interelated, but what do u do. I dont really care about having an EGR valve and i wanna delete the smog pump seeing as i dont have cats or anything. Can i just take the EGR valve off and plug the holes in the TB any other vac lines associated with that and the smog pump? Im stuck and dont know what to do....any help would be sweet!

rd · Apr 6, 2004

I would suggest fixing all of it.

For the egr, Ford egr pressure switches seem to fail often. I have 3 obd 2 Fords, 96, 97 and 02, and all have had the DPFE sensor fail. (Differential pressure exhaust gas sensor)

There is really no performance to be gained from removing it, as it is commanded off at wot anyway.

I would attempt to remove the valve, and tubes, etc, carefully, and clean or replace the valve. If left, over time, these threads can be a pain to remove.

Reinstall the valve if it tests ok, ie, does not leak vacuum. Fix the other items, and see if the code clears. If the valve tests ok, and the code reappears, change the pressure switch/sensor and or, the vacuum solenoid. On the first two I did all the diagnostics and testing, on the third, I changed the sensor, then cleaned and tested. Much faster and worked the same.

If you start removing things, it will make future code based troubleshooting much more difficult and much less reliable.

88stangmangt · Apr 6, 2004

not to mention if you need! emissions test every 2 years then your car needs it or you can take it off till inspection time.

ninety15.0 · Apr 6, 2004

Thanks for the info...that makes a lot of sense. I would really like not to have to remove it but im not sure how to check all that stuff. I talked to my mechanic today and he said that all of those codes may be caused my a bad ground issue. Because i got a code for fuel pump relay failure as well. He said they are all in the same area. Who knows im going to go take the EGR valve apart right now and see what i can do to clean it out. Does anyone know about the grounds and wiring for this circuitry? Any help would be sweet! thanks fellas

jrichker · Apr 6, 2004

Code 34 EGR voltage above closed limit - Failed sensor, carbon between EGR pintle valve and seat holding the valve off its seat. Remove the EGR valve and clean it with carbon remover. Prior to re-installing see if you can blow air through the EGR valve by mouth. If you can, replace the EGR valve ($85-$95).

Grounds are important to any electrical system, and especially to computers.

1.) The main power ground is from engine block to battery: it is the power ground for the starter & alternator.

2.) The secondary power ground is between the back of the intake manifold and the driver's side firewall. It is often missing or loose. It supplies ground for the A/C compressor clutch and other electrical accessories such as the gauges. Any car that has a 3G alternator needs a 4 gauge ground wire running from the block to the chassis ground where the battery pigtail ground connects.

3.) The computer has its own dedicated power ground that comes off the ground pigtail on the battery ground wire. It uses a barrel type quick disconnect connector inline with the battery ground pigtail. Due to it's proximity to the battery, it may become corroded by acid fumes from the battery.

4.) The engine mounted sensors have a common separate ground. This includes the TPS, ACT, EGR, & BAP/MAP. These sensors share a black/white ground wire that connects to computer pin 46.

5.) The O2 sensor heaters have their own ground (HEGO ground) coming from the computer. This is different and separate from the O2 sensor ground. It comes out of the fuel injector harness near the EGR valve.

6.) The TFI module has 2 grounds: one for the foil shield around the wires and another for the module itself.

7.) The computer takes the shield ground for the TFI module and runs it from pin 20 to the chassis near the computer.

8.) The computer's main power ground (the one that comes from the battery ground wire) uses pins 40 & 60 for all the things it controls internally.

If you have access to a digital voltmeter and would like help diagnosing grounds, make another post and I will try to help.

88stangmangt · Apr 6, 2004

jrichker said:
Code 34 EGR voltage above closed limit - Failed sensor, carbon between EGR pintle valve and seat holding the valve off its seat. Remove the EGR valve and clean it with carbon remover. Prior to re-installing see if you can blow air through the EGR valve by mouth. If you can, replace the EGR valve ($85-$95).

Grounds are important to any electrical system, and especially to computers.

1.) The main power ground is from engine block to battery: it is the power ground for the starter & alternator.

2.) The secondary power ground is between the back of the intake manifold and the driver's side firewall. It is often missing or loose. It supplies ground for the A/C compressor clutch and other electrical accessories such as the gauges. Any car that has a 3G alternator needs a 4 gauge ground wire running from the block to the chassis ground where the battery pigtail ground connects.

3.) The computer has its own dedicated power ground that comes off the ground pigtail on the battery ground wire. It uses a barrel type quick disconnect connector inline with the battery ground pigtail. Due to it's proximity to the battery, it may become corroded by acid fumes from the battery.

4.) The engine mounted sensors have a common separate ground. This includes the TPS, ACT, EGR, & BAP/MAP. These sensors share a black/white ground wire that connects to computer pin 46.

5.) The O2 sensor heaters have their own ground (HEGO ground) coming from the computer. This is different and separate from the O2 sensor ground. It comes out of the fuel injector harness near the EGR valve.

6.) The TFI module has 2 grounds: one for the foil shield around the wires and another for the module itself.

7.) The computer takes the shield ground for the TFI module and runs it from pin 20 to the chassis near the computer.

8.) The computer's main power ground (the one that comes from the battery ground wire) uses pins 40 & 60 for all the things it controls internally.

If you have access to a digital voltmeter and would like help diagnosing grounds, make another post and I will try to help.

man try makeing post's like that everyday 4000 times

ninety15.0 · Apr 6, 2004

WOW...thanks a bunch for all that info. Im heading out there right now to see what i can do. IM going to remove the EGR and clean the thing out...and then check all the grounds to the tps, act, egr, and map sensors. I think either way if the 02 sensor is messed up im going to need to replace it right? so what i think im going to do is figure out the egr valve problem....then do my fuel pump rely circuit problem...then do all my smog pump delete crap....and then fix 02 sensor last so i dont go threw a bunch of them while i still have problems. Thanx so much for the info and i will let u know how it turns out.

ninety15.0 · Apr 6, 2004

Ok well i pulled the EGR valve from the TB...brought it inside and soked it and clean it all out. IT was NASTY! So im not sure if its working right though. When i suck on the vac fitting on the top of the valve the pintle goes up into the valve and the diaphram gets smaller. When i blow out on it very lightly the air goes right through, but when i blow on it medium the pintle is where it shoud be and the fills up and the diaphram holds the air. but when i blow hard it doesnt seal as well and i can hear air comming out. What does that mean good or bad....how hard does the car blow on that valve? But heres the other deal....two of the small little vac lines going to two of the check valves on the smog pump lines are broken. the vac lines going to the EGR and the manifold are fine though. Im going to remove all of that smog pump stuf this weekend so what should i do with the broken vac lines for those check valves? suggestions would be great thanks a lot.

88stangmangt · Apr 6, 2004

might have to re-place them all but i know it is supose to close a WOT.

jrichker · Apr 6, 2004

Blow on the flange side of the EGR. If it leaks, there is carbon on the pintle valve seat. All you can really do is to replace it.

EGR failure...can i just take it off??

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