I have an 06 LBZ. Fuel mileage sucks especially when towing my 10k fishing boat. We are talking 14-15 avg unloaded, 7-8 towing. My 02 LB7 wasn't much better either. I want to try a Predator tuner, but know I need exhaust to combat egt's with it. I have guages, just need to install them. I do NOT want a loud truck, if I did I would have bought a Dodge, but I want low egt's and a mileage bump, power stock is fine but the throttle response sucks. I am thinking of a cat back simply for quiet reasons, but will go turbo back IF it is significantly worth it. My only mod from stock is 265 BFG's, which cost me 2mpg by the way. Thanks for the help. MBRP is the brand I'm leaning towards, but would consider Kennedy or Magnaflow for the right price point. I really don't see how anybody can be getting 20 mpg with these trucks, I have 3 friends who all have the same story as me. By the way, I want mileage for RANGE, not because I'm worried about saving 5 bucks on a fill up.

If you want it quiet, go with a cat back system. Mine's capable of 22 mpg highway at 70 mph.

The biggest restriction is gonna be the muffler, not the cat. Removing the cat will make it ALOT louder.

There's a million exhaust threads here, within this section currently. Take a gander at whats already in here...

Here's the most recent for your application.

http://www.dieselplace.com/forum/showthread.php?t=197562

The biggest restriction is gonna be the muffler, not the cat.

How do you figure?

What about just a muffler? Is 31/2 to 4" that important for egts? BY the way, I did read that thread above, as well as EVERY thread for 17 pages back, I believe. I am still confused as to the benefits of removing the cat as well. Thanks for the quick replies.

The muffler has baffles. Cats are a flow through design. Many vendors here have said it in the past that the biggest restriction is the muffler.

Both suck power. If the definition of flow through is that there are no baffles, then yes, a cat is flow through... but it has zillions of tiny holes the exhaust has to squeeze through.

Try removing both and see how it sounds.

Russ