Anybody ever fix EGR problem on 3.4L

[pontiac nino]

All this 3.4 computer glitch prob. makes me feel like my 3.4 is crap. :(

BTW, out of curiosity has anyone here taken there car to get checked with a code reader when a ses light goes off? :rolleyes: Or atleast made someone stay there till it throws a code?

[StudlyCamaro]

if the light comes on and then goes off later it still stores the code in the computer's memory

my light has been on and off when iver scanned it , and i get the same results each time

[ideutsch]

Just adding my $.02... I have a 3.8, but went through the same problems (stumbling under load, misfire at high rpms, solid SES light). I cleaned the fuel injectors, replaced plugs and wires, cleaned the EGR valve...nothing worked. Then I inspected the coil packs, specifically the one that I was getting misfire codes for, and it was corroded. After replacing it, the car ran great and I still haven't seen an SES light after 5 months. So if you haven't checked the coil packs yet, might want to give it a try...

[pontiac nino]

Originally posted by ideutsch:
Just adding my $.02... I have a 3.8, but went through the same problems (stumbling under load, misfire at high rpms, solid SES light). I cleaned the fuel injectors, replaced plugs and wires, cleaned the EGR valve...nothing worked. Then I inspected the coil packs, specifically the one that I was getting misfire codes for, and it was corroded. After replacing it, the car ran great and I still haven't seen an SES light after 5 months. So if you haven't checked the coil packs yet, might want to give it a try...

Thats what I thought too, although he didn't say he had a misfire/rough idle/etc. just that he threw a code between 50-60 mph so i assumed he had no other symptoms. [img]graemlins/popcorn.gif[/img]

[95]

Thats right I have no other problems Im just getting the code when I let off at like 50-60mph. Its probebly a glitch like StudlyCamaro said. It goes away when I turn the car off the I have to go 50-60mph then let off and the light will come back on.

[pontiac nino]

Originally posted by 95:
Thats right I have no other problems Im just getting the code when I let off at like 50-60mph. Its probebly a glitch like StudlyCamaro said. It goes away when I turn the car off the I have to go 50-60mph then let off and the light will come back on.

Funny thing, was going about 50-60mph, suddenly I my car throw a code, thus it was about 11PM and no shops being open at the time.......wow, but im thinking it's a sensor (O2/air pump) since I have been having trouble with this, even funnier my car ran better with the code. [img]graemlins/stickpoke.gif[/img]

[MississippiMaro]

I have researched this all over the net, and the conclusion i have come to is that the carbon build up in the EGR valve, the feeder tube and the tube going to the exhaust manifolds throws the SES and the solenoid codes. I've relaced it once and cleaned everything associtaed with the EGR system and it only kept the SES light at bay for 6 months.
I'd be interested to see how many people have EGR probs and what grade of gas they use. i'll bet people who use higher octane gas for the life of the car have fewer problems.

[StudlyCamaro]

humm... i never bothered the pipe that leads into the EGR... you might be onto something

[95]

You might be right I do use the lowest grade gas but thats what it should use isnt it? I havent cleaned any of those parts that head toward the egr. Then again I wish I could get rid of it so I could change my spark plugs more easly.

[viper98885]

I used to have the same problem back in the day before the headers and stuff. Now, since the headers, it has not come on. Shortly after the headers though, I did throw in a block-off plate between the intake manifold and the tube leading to the intake manifold from the EGR vale.

[MississippiMaro]

anyone know where an EGR Sim can be had?

[Harbin1]

ZZPerformance.com in the exhaust section.

I get the same EGR solenoid 1,2,3 malfunction codes almost everyday. I leave my scanner hooked up and I check the history codes about once a week just to make sure nothing new has popped up. I've almost always used 93 octane. I've got Hypertech programming installed so I kind of have to. My mechanic looked at the EGR and couldn't find the problem. He replaced it with a new one but that didn't fix it so he tried a new computer and that didn't fix it either. He didn't charge me anything since I still had the problem, Is that service or what!! :D

Has anybody got ZZP's EGR sim on a 3.4? I emailed them and they replied "it should work," but I'd like to know for sure if it is compatible with my motor before I drop $70.

[95]

Viper98885 does the blockoff plate prevent the light from comming on? Cause if it does its a cheap way to fix that prob.

[PewterBird]

My service manual doesn't give me any info on the 3.4. But I can give you some info that might be transferable.

It looks like the computer wants to keep the voltage of the sensor between .14 and .4 volts. I might be possible to wire up a fake voltage reader with some resistors. Kinda like an O2 sim. I don't know enough about the 3.4 system or have enought electrical engineering knowledge to design anything, but it might be a good point in the right direction for someone with more info.

Below is the circuit description for the 3.8
----------------------------------------------
The PCM monitors the EGR valve pintle position input to ensure that the valve responds properly to commands from the PCM and to detect a malfunction if the pintle position sensor and control circuits are open or shorted. If the PCM detects a pintle position signal voltage outside the normal range of the pintle position sensor, or a signal voltage that is not within a tolerance considered acceptable for proper EGR system operation, the PCM will set DTC P1406.

Conditions for Setting the DTC
EGR Feedback is less than 0.14 volt at any time.
OR

EGR Feedback is 0.4 volt greater or less than the EGR Closed Valve Pintle Position when the Desired EGR Pos is commanded to 0%.
OR

Actual EGR Pos is 10% greater or less than the Desired EGR Pos.
Any of the above conditions present for longer than 20 seconds.
Action Taken When the DTC Sets
The PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed.
The PCM will store conditions which were present when the DTC set as Freeze Frame and Failure Records data.
Conditions for Clearing the MIL/DTC
The PCM will turn OFF the MIL during the third consecutive trip in which the diagnostic has been run and passed.
The History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
The DTC can be cleared by using the scan tool.
Diagnostic Aids
Check for the following conditions:

Open EGR ignition filter circuit. An open in the EGR ignition filter circuit will cause erratic EGR Position Error readings while the EGR valve is operating. With the ignition ON, a test light should illuminate when connected between ground and the EGR ignition filter circuit at the PCM connector. If not, locate and repair the open in the EGR ignition filter circuit.
Excessive deposits on EGR valve pintle or seat. Check for deposits that may interfere with the EGR valve pintle extending completely or cause the pintle to stick.
Poor connection or damaged harness. Inspect the wiring harness for damage. If the harness appears to be OK, observe the EGR actual position display on the scan tool while moving connectors and wiring harnesses related to the EGR valve. A change in the display will indicate the location of the malfunction.
EGR Valve Icing. EGR valve icing can occur during cold ambient conditions. An EGR valve icing condition will affect EGR system operation by causing the pintle to stick in the closed position. If DTC P1406 sets, EGR system operation may be inhibited for the remainder of the trip.
Reviewing the Fail Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.

[95]

I think the prob is associated with carbon deposits in the way of something because someone posted that they had cleaned everything up including the tube that chanels exhaust to the egr valve. They sed that took care of the prob for 6 months then started again, but You may be on to something with those resistors.