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Discussion Starter #1
egr valve pressure sensor melted on a 3.8L v6. if my memory serves me right this is caused by a plugged cat? kinda runs like it has a plugged cat. am i on the right track? anything else to check?
 

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Hardcore Web Wheeler
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Not sure what you're working on for lack of info. Because you said "pressure" and not "position" I assume you're talking about the DPFE sensor. I've never seen one melt myself but it wouldn't suprise me. I've replaced dozens of them.
It would sound more to me like a EGR pintle stuck partially open would be more likely the culprit. As that would give prolonged exhaust flow and heat. It would also run like crap because it is like having a vac leak.
However if you've heard of plugged cats causing it just hang a vac gauge on it and accel, you should have your answer in a couple of seconds.
 

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Discussion Starter #3
motor is a 1988. and the sensor im talking about is the one that sits on top of the egr valve connected with a rubber hose.
 

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FoMoCo MoFo
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That's the egr position sensor.
 

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Yulp, thats the position sensor. I suppose a plugged cat could cause it to melt because of the excessive exhaust flow when the EGR is open.
However I'd still think it's more likely that the EGR is stuck partially open allowing hot exhaust gas all the time. Usually happens when a little piece of carbon lodges in the pintle.
Buy an EGR gasket, clean the valve, and reinstall the valve to see how it runs. If it still runs bad throw a vac gauge on a manifold port and accell real hard. If you see pressure at any point then the cats probably plugged.
 

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Discussion Starter #6
well ill give that a shot this weekend when i have some time. but just to avoid any confusion heres some pics of the egr position sensor and the egr pressure sensor. at least this is how they are listed on vatozone and pep boys

this is the one im talking about and they list it as a pressure sensor


this one is listed as a position sensor


NOT TRYING TO SAY YOUR WRONG. I JUST WANT TO AVOID CONFUSION
 

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FoMoCo MoFo
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The white one is what goes on the valve... so if that's the one that melted...
 

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Wow, I've never seen that style sensor before. It's very similar to the DPFE but only has one port. The DPFE uses 2 ports and senses the difference in pressure to determine flow.

Regardless, the theories behind the meltdown remain the same. I'd chisel the carbon out of that EGR then try the Vac gauge to see if the cats plugged. Make sure you do it with a new sensor installed though, you dont want a bad one commanding the EGR open all the time and causing further meltdown.
 

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also clean out the EGR ports and the hole which it mounts to as well while you are at it. On most of them you can move the pintle up and down by hand to make sure its moving easily and smoothly..
 

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Discussion Starter #10
ok so the egr is fine. i removed it and found it was clean as a whistle. hooked up a vacuum pump and it works flawlessly. since the port from the egr to the sensor is on the exhaust side of the egr valve the cat idea makes alot of sense. so next ill remove the cat and see if its that. ill let ya know
 

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Yup you are on the right track, I've been a Ford tech for 20 years and I saw that problem quite often back in the day.
 
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