This may be a dumb question but do mufflers ever go bad? Reason I ask is my 06 with 230k miles on it has the original exhaust. I beat the cat out a few years ago. (that sentence sounded weird lol) Anyways I digress. I use the truck for towing is there anything to be gained by redoing the exhaust or replacing the muffler. I like the stock sound just fine without the cat but was curious if the muffler ever gets full of gunk like the cat can. I run mat gearhead 8k tune on a stock truck.

Thanks

 

Just rust from the inside out. The moisture is the enemy. If the rest of the pipe looks good a new muffler wouldn't hurt with your neutered kitty intact.

 

I would highly recommend you replace your stock exhaust, especially, if you are running a tune. I have a MBRP 4" S/S T-back no cat exhaust on my truck for the past 10 years. It looks a little rough on the outside but it is solid from turbo to tailpipe considering the amount of road salt it sees. The muffler is like a straight through glass pack muffler. It is quiet when cruising and noisy when you get on it. It is one of the best upgrades you can do to the 6.0. You will see a noticeable improvement in throttle response due to opening up the exhaust. Exhaust backpressure is what inhibits stock 6.0 performance. It made a world of difference in my truck's performance. I run the SCT street tune in the PCM and the Ed's FICM repair ATLAS 80 FICM tune. The FICM tune is AWESOME!!!!!!!

Ed