cat delete?

[chrispugs1967]

I know this is a popular subject but i was thinking about this. I have the cat delet pipe and the down pipe on my 03-6.0. I just had to put the cat back on for emissions. Are the studs on the cat just pressed into it, what a pain in the ass to get it back out, I had to drop the whole exhaust to slid it out. My thought was to pop the studs and use shorter bolts for next time i need to do this. Second question is when i put the cat back on it still sounds the same, a nice whistle, im assuming its the down pipe thats giving me the sound, do i even have to take the cat back out. Just wondering what your thoughts are.

 

[WD40]

What does the cat do to your MPG and your EGT's when pulling a heavy load?
If it's not much, I would keep it on.
Doug

 

[chrispugs1967]

I just put the cat back on this week so i haven't noticed that yet. i'll leave it on and check MPG next fillup.

 

[MJ Synthetics]

The cat will usually drop your fuel mileage. In most cases that I have seen the cat out improves milage and efficiency with lower egt's.

 

[798er]

I put a 4" turbo back no cat sys. on my 6.0 right after a bought it so don't know what the milage might have been. With my equp. load of 1 ton + in get around 11.5 mpg avd. according to the computer.

 

[chrispugs1967]

I'm not even worried about the milage differance, its more about haveing to change it out every 2 years for emmisions. I'm gonna put the "test pipe" back on and rip those studs off the cat and figure out how to use shorter bolts to switch it out faster. I'm saving for the 4" cat back exhaust.