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.
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.
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
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.
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
A forum community dedicated to custom off-road vehicle owners and enthusiasts. Come join the discussion about trail reports, builds, performance, modifications, classifieds, troubleshooting, fabrication, drivetrain, and more!