EGR Code set in computer - question

potshotscott

Registered User
Quick question for the brilliant automotive engineers and experienced shade tree mechanics on the forum. I have a '94 with a check engine light on. The code directly relates to the EGR valve. I have replaced the sensor but no joy. Today I pulled out the EGR valve and stem that connects to the exhaust manifold. There is a 2 inch crack on the bottom of the stem. My question is this - would the crack cause an issue that would make the DPFE code pop? The two stem pipes go in and out of the DPFE. Is/would the crack cause a pressure related problem here?

FWIW the stem is over at dad's getting welded this week and will go back in the car with a brand new EGR and new DPFE (since Autozone warrantied it back).

If this doesn't work I'm going to look at EGR deletion - perhaps that will get me closer and closer to buying a quarterhorse.
 
I'm not sure about the 94 but my 90 gave me a CEL for EGR for the longest time. It turned out to be a small solenoid on the firewall on the passenger side. It had a little filter on it that had turned to crud.
 
Dumb question but the acronym DPFE is throwing me, what is it?

From google:
Differential Pressure Feedback EGR Sensor - it's basically like a MAP or a barometric pressure sensor for your EGR system - it's there to measure the flow of EGR.

-g
 
As in what we normally call the EGR sensor?

Ok that is different from my 90 that one has 2 ports mine has one, so I get the differential pressure thing.
 
I'm not sure about the 94 but my 90 gave me a CEL for EGR for the longest time. It turned out to be a small solenoid on the firewall on the passenger side. It had a little filter on it that had turned to crud.

Do you have a more official name for this part? I'd like to find it....
 
According to Henry they call it a differential pressure feedback sensor DPFE.

Try just EGR sensor for a 94 Super Coupe, that's the name many of us know it by. If it wasn't for KMT I;d have no clue what it was.
 
Thank you - I know what you mean now. I have already changed out the EGR and DPFE. Got my stem welded (thanks Dad) and am going to try and get it back on the car tonight.
 
The fact your stem was leaking may very well have thrown off the EGR and set CEL light....here's hoping!!!
 
The fact your stem was leaking may very well have thrown off the EGR and set CEL light....here's hoping!!!

I'm happy to say that the problem is fixed. I replaced the EGR, DPFE and had the stem welded. After putting it all together I realized I still had a vacuum problem and found the vacuum hose that goes to the input of the EGR was unplugged at the output of the vacuum reservoir that is next to the steering linkage above the left hand catalytic converter. I'm left wondering if that hose being off was the problem the whole time. I suppose I may have knocked it off/loosened it when I replaced the transmission in my car. It's been going on so long I don't exactly know.

One thing is certain - the car is not quick to overheat now and the CEL is no longer lit.

Thanks for the support everyone. Now its time to find a transmission cooler and new shocks and struts!
 
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