hi guys i own a 2006 gmc sierra 2500hd 4dr , i installed headers + cam.. anyways the catback is really expensive so i have 2 alternatives i want the best performance! without having so much noise..

1) keep cats , install "borla or another brand" muffler
2) remove cats = straight pipe

Regards

 

remove cats and get a borla or magnaflow

 

ok then the straight pipes is too noisy and it could cause a damage to the O2 sensor so go with the flow master "cheap is nt it"

 

The cats on these trucks aren't as restrictive as you might think, they actually flow pretty well. If you remove them it won't harm anything though, but you will need the PCM tuned to turn off the rear O2's not to report or you will get codes. If noise is a concern, get a big case Magnaflow muffler, it's a straight through non-restrictive design with a nice tone...not very loud at idle, but deep and tight sounding at WOT. If you do decide to lose the cats and the noise is too much for you, you could always replace them with some resonators that will help bring the noise level down...of course the price goes up though.

This website offers "non-catalytic" converters at decent prices:

www . siliconeintakes . com