Ok fellas, ya'll have helped me out before. I have a '97 F250 4X4, 5.4. I also have a 5th wheel camper that i have now pulled twice with it. I know the gas mileage is not going to be great, but I didn't think it would be quiet as bad. I have done a tune up, had the egr replaced, and ports cleaned. Cleaned maf, also replaced 2 cops. The truck seems to run good, but seems like it's missing something especially with a load behind it. It also has a strong odor, especially when at idle. This was my first big road trip with the camper, and it was very noticable that when you were on much any of an incline that the thing just didn't seem to have the power it should. I would lose anywhere from 5 to 15 mph. Maybe ok, but just don't seem right. I have questioned the cats before, and was wondering if this could be the problem? I'm also thinking about going with duals. Will this help me any at all, or am I just spinning my wheels here? I would also like to know what the symptoms of a stopped up cat are and what problems can it cause? Just curious there. Should have mentioned that it has 155k on it. Thanks.

 

Sounds like you do have a CAT or CATS problem. One way I check is with temp. I read the temp going into the CAT and the temp coming out. The bigger the temp difference, the bigger the blockage.