Exhaust Convertor

[Makers]

Can anyone tell me if the following is true, I was told that by removing the factory exhaust convertor you will gain 25 to 30 hp? Of course the truck will now need to be registered as a commercial truck if the converter is removed, also, will this void the factory or Cummins warranty?

Thanks

Mark

 

[KBrasch]

here is what i did i took off my cat and took all of the guts out and reinstalled with no effects on the motor power or mileage. I then too my muffler off and put a muff delete pipe on and noticed loss of fuel mileage ie. 2-3 accross the board, mite have more power cant really tell with out dino, but did notice egts down 200-300 degrees. not much louder just during a long tow.

I talked to dc they said would only void exhaust warrenty and asked about fuel mileage loss and said that i need to reinstall muffler as these new engines need back pressure?

i have an 06' mega laremi with 5. 9 auto 48re.

 

[Cattletrkr]

here is what i did i took off my cat and took all of the guts out and reinstalled with no effects on the motor power or mileage. I then too my muffler off and put a muff delete pipe on and noticed loss of fuel mileage ie. 2-3 accross the board, mite have more power cant really tell with out dino, but did notice egts down 200-300 degrees. not much louder just during a long tow.
I talked to dc they said would only void exhaust warrenty and asked about fuel mileage loss and said that i need to reinstall muffler as these new engines need back pressure?
i have an 06' mega laremi with 5. 9 auto 48re.

I haven't heard that line in a while. I thought it finally died out. You shouldn't be losing mileage by removing the muffler unless you're unintentionally pushing the go pedal a little harder trying to hear it.

I yanked my cat after 150K... it wasn't plugged at all and I wish I could put it back on. Less drone with it inplace. Absolutely no noticeable performance difference.