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Discussion Starter #1
I have a 94 4.6 and I am getting a persistent P0402 (EGR excessive flow) even though I had the DPFE sensor replaced and a new EGR valve replaced, also the tubes are said to be clear and there are no vacuum leaks. I've had the car for 5 years got it with 37k on it, it now has 72k. I have also gotten codes that are not listed. I understand the 94's computers are Gen 1 and some have problems due to them being somewhat experimental. So what does everybody think?
 

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When you say, "the tubes are said to be clear", did you check them yourself? I get that same code and here's is what the problem turned out to be:

The EGR tube that goes across the back of the engine (so hard to get to)? Well, there are two little tubes that come off the big tube with an orifice between them. Try to blow into those two little tubes that go to the DPFE sensor because one of mine was clogged. I'm not sure, but the orifice could have been plugged on mine too, I don't know.

I'm pretty sure you have the same issue. Check it out and let us know!
 

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Ive dealt with at least 5 bad 94/95 EEC's - 4 of those had the Stuck injector driver = Blowing clouds of white smoke out the exhaust. The other one would not control the IAC valve and stay running at idle..

Code 0402 is common .. could be the DPFE, EGR, or the EVR solenoid. Sometimes it just goes away on its own.

.. but you said there are more codes that are not listed ??
 

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Ive dealt with at least 5 bad 94/95 EEC's - 4 of those had the Stuck injector driver = Blowing clouds of white smoke out the exhaust. The other one would not control the IAC valve and stay running at idle..

Code 0402 is common .. could be the DPFE, EGR, or the EVR solenoid. Sometimes it just goes away on its own.

.. but you said there are more codes that are not listed ??
Wow, that's good information about the stuck injector driver. You would think that would foul out the plug drowning it in all that fuel and make black smoke like when a carb is too rich. Learn something new every day...

+1 on the code 0402, that is all very true. I just know I had a hard time finding the problem on mine - I replaced EGR, DPFE, even MAF before I figured out it was the little clogged DPFE tube. But I've seen EGR valve problems cause it too, but you've replaced that, so...
 

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Wow, that's good information about the stuck injector driver. You would think that would foul out the plug drowning it in all that fuel and make black smoke like when a carb is too rich. Learn something new every day...

+1 on the code 0402, that is all very true. I just know I had a hard time finding the problem on mine - I replaced EGR, DPFE, even MAF before I figured out it was the little clogged DPFE tube. But I've seen EGR valve problems cause it too, but you've replaced that, so...
The gas that gets dumped into the exhaust should be heated up by the Cats and turned into water .. which is what produces the white smoke.

The biggest indicator is the engine running rough, strong fuel odor and no fuel leaks outside of the car ( except for the water that will drip out of the cats ) ... running this for a while could cause damage to the cat's and O2's .. not to mention all of the smoke being sucked up in through the EGR.

Oh yeah .. no check engine light either for the BAD EEC. You can tell which cylinder is getting the fuel by checking the plugs - but if this is the case, I could definately replace the EEC, change the Oil and Plugs and then re-test the vehicle - it will usually still smoke for a day or so afterwards.
 

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Ive dealt with at least 5 bad 94/95 EEC's - 4 of those had the Stuck injector driver = Blowing clouds of white smoke out the exhaust. The other one would not control the IAC valve and stay running at idle..

Code 0402 is common .. could be the DPFE, EGR, or the EVR solenoid. Sometimes it just goes away on its own.

.. but you said there are more codes that are not listed ??
So could that be the problem with my car? When its warmed up and i accelerate a cloud of white smoke comes out the exhaust that smells like gas. And i got a code that my bank 2 is running lean today. Could that be my problem?
 

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So could that be the problem with my car? When its warmed up and i accelerate a cloud of white smoke comes out the exhaust that smells like gas. And i got a code that my bank 2 is running lean today. Could that be my problem?
A stuck injector is constant, not just when warmed. It will feel like a dead cylinder. So if the car runs seemingly ok and you have white smoke primarily on acceleration, it's likely the valve stems seals.
 

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A stuck injector is constant, not just when warmed. It will feel like a dead cylinder. So if the car runs seemingly ok and you have white smoke primarily on acceleration, it's likely the valve stems seals.
Mine only blows smoke when I first take off after letting it idle; even the short time it idles at a red light. I'm getting sick of adding oil ever 2-3 weeks and I will finally put the valve seals in I bought months ago soon, honest! lol

But, back on topic, my car runs very smooth and strong for stock, so I guess all MY injectors are working, right?
 

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Well its not always when warmed up I dont think but it does feel like its running without a cylinder and the idle is bad sometimes too
 

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Discussion Starter #14
Where would I find the EVR selinoid, it's the only thing I have'nt changed with reguards to the whole EGR system. Also, you guys familiar with the " T " junction in back by the fire wall? I replaced that 2 years ago but there are 3 hoses that plug into it, one I think is the EGR hose and the other 2 I don't know where they go or what they do, could one of those 3 hoses need to be cleaned out?
 

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Discussion Starter #16
ok thanks, so I'll check the " T " itself and see if that went bad again. So, since my EGR valve is new, the DPFE is new what else can I do to correct the P0402 code I'm getting ( EGR EXCESSIVE FLOW), are there any lines or tubes I have to check? When I clear the code the check engine light goes off as long as I keep the engine running, it runs rough though, it idles like a big block with a wild cam in it, the light stays out untill the next time I start the engine, then it comes back on in about 45 seconds. So thats about it, any input would be greatly appreciated.
 

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There is a way to test the EVR .. I thought you try to blow air through it while disconnected and it shouldnt allow air to pass through. Then energize the solenoid and see if air passes when its suposed to be open. If it doesnt work like it should, replace it.
 

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Try disconnecting the vacuum line from the EGR valve itself. If the engine smooths out, then you know that vacuum is getting to the EGR valve, meaning the EVR is bad. If it doesn't change, you may have a bad EGR valve (new != working). Did you check before installing it that it didn't allow anything through when closed?
 

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Discussion Starter #19
no I didn't check, can't get back there now I have a torn cartilage in my knee, but I will as soon as I am able. Thanks.
 
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