[HK45]

I wanted to purchase a mbrp 5 inch cat back system for my 2006 LLy. I was wondering if that is to much for a truck that just has a cold air intake kit. I read alot about you need to have 4 inch for stock and 5 inch for chipped trucks. As of know i had the muffler removed and had a peace welded in, the problem is the peace that is welded in has big bends and is a little smaller then the stock pipe, overall it made a big different doing just that . Do you guys feel i should go with the 5 inch cat back or leave it the way it is.

 

[TheBac]

Your thread title is more than a bit misleading.....

A 5 inch exhaust is a bit of overkill for a stock truck, but it shouldn't hurt anything. A 4 inch exhaust is fine.

I guess you have to ask yourself, "What are my future plans?"

 

[coens]

I have a 2006 LLy also and want to install the 5" cat back sytem on a stock truck, so that in the future I can add a tuner and air intake, will it cause any drivability problems? or shoud I just go with a 4"

 

[Kennedy]

IMHO a cat back system is a waste of money. The best benefits will be realized without a catalyst. Not legal, but...

 

[ssduramax]

IMHO a cat back system is a waste of money. The best benefits will be realized without a catalyst. Not legal, but...

no cat is good for "off road use" I'm sure that everyone here that has lost a cat uses their ride in this manner.

 

[Mark Craig]

HK45,

Five inch looks great, but be prepared it'll be loud as compared to a similiar designed 4 inch system. FYI, A 4 inch will support up to 500 RWHP too. A cat back is a good addition, it'll get you approx 75-80% of the EGT loss and HP gains of a catless system. It'll also be pretty quiet, removing the cat for off road or racing use is the best way to get the lowest EGT's but lots of folks don't want to go that way for legal reasons. The current cats flow great as compared to cats of just a few years ago, not that they aren't restrictive they are just a whole lot less restrictive than the cats from the past. We stock all the MBRP systems in aluminized, 409 and 304 stainless. Singles and duals, call us if you have any questions etc.

Mark @ DPPI

 

[_nar_]

Your thread title is more than a bit misleading.....

Indeed, changed it slightly...

 

[predatorhummer]

I have a 5 inch on my 06 LBZ with the occasional P0401 code. Just waiting to find the best blocker plate and stick. Can anyone help with that? My 5 inch is not loud either on the new truck. My 2002 LB7 was loud. This one sounds like a built big block.