Got to replace the convertor on my E150, 300cu.in. 6cyl. van. OK...I know it's not an F150, but the driveline is similar.
I've been getting less and less power, and have to give it a lot of pedal to move down the road. Plus the exhaust sounds like a hoover. There's very little pressure coming out of the tail pipe.
What causes this? It's a '92 with 82,000 miles on it.
Do these just decide to go bad?
Anybody know?

 

converters can plug up from old age or if the engine is running rich. i had the fuel pressure regulator in my 302 go bad one time and the engine was getting around 70 psi of fuel (~40 is normal) and it caused the engine to run rich and plugged the cats after 10 minutes of driving.

 

WOW! I don't think its running rich, as it just passed the E-check two months ago w/good numbers. It did sit without starting for a few months though.

 

If your converter came unglued, you'll probably want to replace the muffler as well.

Happened to my 89 Ranger, 2.9L, replaced the converter and found the Ranger wasn't towing a roadster on a car trailer over the big grade out of the San Joaquin Valley into L.A. as well as it did before.
Just general running around showed a 10-15% drop in gas mileage.

Stuck on a glasspacked Turbo Muffler and the towing was as good as it had been.
Gas mileage went back to where it was.

I've found since that it's very common for the failed converter parts to lodge inside the muffler and clog it up.

C9