I have a 2002 Ford Taurus, 3.0L DOHC...

The DPFE Ref side MELTED...I replaced the DPFE. Now, with the hoses connected, when the car is revved high, the high presuure hose blows off the the high pressure side of the DPFE.

I have absolutely no idea why this is happening. I have replaced the EGR valve, the EGRVR, the IAC solenoid. Does anybody know why this would be happening?

 

So, I put clamps on the hose - one on the side coming off of the tube from the exhaust manifold and one on the DPFE side. The hose ain't gonna come off!!

But, now the car will not exceed 2000RPM no matter how much the accelerator is depressed/how far the throttle plate is opened up...

What gives?!

 

Sounds like restricted exhaust/Cat. (exhaust over pressure)... Pull the O2 sensors and see if it runs better under load.. You can pressure test the exhaust system for 'flow' at the O2 sensor to verify a bad Cat.....

 

I found another forum that has the exact same events - for him his rear cat was severely restricted.

First time I have ever encountered a restricted cat...

 

I dropped the front and main cat pipes. I did not take off the rear cat because it is made as a part of the rear exhaust manifold. When I unbolted the pipes, THERE IT WAS! as near as I can tell, the rear cat had disintegrated somewhat and the contents were in the pipe leading to the main cat.

After cleaning out as much of the stuff as I could, I have reassembled the pieces and the car is running pretty good. I plan on driving it for a couple drive cycles to see if I start getting cat codes.

There is still some restriction - you can hear the 'sound' of it when the engine is under heavy load such as going up a hill. I will probably have the main cat replaced with a universal unit. I will eventually have to replace the rear cat, which means replacing the rear exhaust manifold.

And so, another Taurus mystery solved...but since it is a Ford, I am sure it won't be the last one...