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Another egr problem

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Coach James

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Jun 24, 2005
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A couple months ago, I posted about a problem with the egr valve on my van. I replaced it and all is well. The Check Engine light came on on my 2002 Grand Prix so I checked it today. p0401 "Exhaust gas recirculation flow insufficient detected". Any chance the opening to the egr valve could just be blocked with carbon? Or is there something more likely that is the culprit?

BTW, my Equus 3150 scanner came in yesterday. So far mighty nice and easy to use. $159 from Amazon with free shipping.

Thanks for any guidance.

Coach
 
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oldtools

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If you put vacuum on the egr valve, you can see the diahragm from the back move. If not, then it is the egr valve. I doublt it is the egr valve since you just replace it several months ago. Have you try cleanning all the tubes/hoses that can have significant carbon builup that clog the flow of exhaust gas. If they are all clean, it can be the vacumm switching valve or the egr temperature/pressure sensor depending on how your egr system is set up.

Right now I am suspecting clogged tubing/hose.
 
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nissan_crawler

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Wichita, KS
oldtools said:
If you put vacuum on the egr valve, you can see the diahragm from the back move. If not, then it is the egr valve. I doublt it is the egr valve since you just replace it several months ago. Have you try cleanning all the tubes/hoses that can have significant carbon builup that clog the flow of exhaust gas. If they are all clean, it can be the vacumm switching valve or the egr temperature/pressure sensor depending on how your egr system is set up.

Right now I am suspecting clogged tubing/hose.
Click to expand...

He replaced it on the van, not this one. Not knowing much about you system, I agree with locking for a plugged passage. When I pulled the engine in my pickup at 200k miles, the egr passage in the intake was 100% plugged.
 
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psychoclaw84

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Valley of the Sun
p0401 "Exhaust gas recirculation flow insufficient detected"

I worked on a 1997 Honda Accord and found that the whole EGR port/passed blocked with carbon build up.

Once I removed the EGR valve and cleaned the port passage way to the the intake manifold it cleared the error.

Check other car forums, eg: Pontiac Grand Prix forums and look for p0401 solutions. You will find helpful members with solutions to your problem.:bounce:
 
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Merkava_4

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I'm almost certain that a 2002 Grand Prix will have an electric solenoid operated EGR valve. After I verified power going to the EGR, the Tech II scanner was deployed to watch the EGR operation. The EGR pintel, which is normally moved by the electric solenoid when the PCM tells it to, was not moving. The electric solenoid was determined to be burned out. A new AC Delco EGR valve was the cure.
 
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srmofo

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those dont usually plug up because the tube is fairly large diameter. Im not saying it cant happen its just not as common as the honda v6 with those little 1/4 passages that run through the upper plenum or a ford.

pop it off and give it a check. Without knowing more history thats where I would start. Sometimes if the EGR is removed, the new gasket will have a screen/filter? over the holes which makes them clog up a whole lot easier.

Im going to assume your code reader isnt bi-directional so search other forums for ways to test its function w/o a scanner
 
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Keep

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Oshawa, Ontario
Its an electric egr. Pull the valve, clean the carbon out, replace gasket with the gasket with the screen in it.

Before you spend $200+ on a new one, hit a bone yard and pick one up for $20.
 
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benjamming

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Clean the valve & intake. Even if it is the EGR (usually not) the passageways still need to be cleaned.
 
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Merkava_4

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The car needs to be put on a Tech II scanner like I said in the first post. You can't tell if the EGR is operating without seeing the movement on a scanner. The scanner will show the opening of the pintel valve in percentage of full open. When I changed mine, all the tubes going to the EGR were clear - no carbon.
 
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