i have a 2005 cummins 2500 6 speed with 373 gears and 35 inch tires
juice attitude aem intake
stock cat and straight pipe after cat
i normally run 600 to 700 empty
lately im running 700 to 950 temp in the same driving conditions
is my cat plugging up the egts are just running hot on level 1 i can easely hit 1000 just eccelerating to 60 mph firmly but not to agressively
any advice would be great thanks i also changed the fuel filter and no change

 

I would check your boots on the turbo system for leaks. If your not getting full boost it could be your problem. Is it smoking heavier? Turbo sound good?

 

runs good no leakes 40 lbs boost miled smoke unless i turn it up
turbo sounds good
what temp is every one els running while eccelrating to 55 mph and cruising down the road
40 psi peak 29 or so getting into it a little

 

your good until the 1200 to 1300 range then you need to worry more, probly the cat, how many miles on it? what level and how long do you run around on normal?

 

level 1 and 2 most with low boost fuel at level 3
50000 miles
my tou hauler 28 ft taho and 4 bikes 1275 deg is easy on a hill

 

When was the last time you changed the air filter or cleaned it?