ooppsss.. you can use an infared thermometer to check your cat, temp. I think if you have more than 75 degrees difference front to rear you can consider this plugged. Someone else might be able to add the correct temp difference if I'm wrong.. Plus if you hear a rattling noise in the area of the Cat. it could mean the honeycomb like material inside has broken up and this will cause it to plug. Been there twice, once with a slant six in an 85 1/2 ton, and once in my 95. Both times the performance was poor..

 

I know on the BMW's I work on, I have a special gauge that screws into the oxygen sensor port before the cat, that registers how much pressure is present. I'm sure Dodge has something along those lines... but unfortunately, that would mean having to visit the dealership. Yes, plugged cats can be a major pain in the butt. Maybe a Midas or similar muffler shop would be able to help you out???

One other thing... fuel pressure. Check your fuel pressure and make sure it's in spec. I seem to remember hearing about the fuel filter/pressure regulator going bad somewhat early on these. Don't know if it's a rumor or not, but it can't hurt to check into.

 

A friend has an infared thermometer I will have him check the temps for me and I will have my mechanic check the fuel pressure. Thanks for the help. If anyone has any other ideas for inproved mileage and power or what could be wrong with this thing let me know.