Muffler Replacement Stock Pipe Size

[Gooseslayer717]

I just purchased the Airraid MIT intake tube for my 2011 Sierra 5.3l and noticed sounds and power immediately after replacing the restrictive and oddly designed stock intake tube.

I am looking to also maximize the exhaust and am not sure if i should just replace the muffler with a better flowing one or replace with a cat-back exhaust.

I am looking to save money and with just a Intake, Muffler and Diablew Tune i do not plan on having too much HP.

Will the stock Exhaust pipe size be large enough?

Is there any way to easily install myself or would it require welding.

Attempted to find online but people seemed to offer different piping sizes for different years and engine sizes.

If the piping is 2.75" as some say, would a 3" in/out muffler fit over the exhaust tubing?

[CamGTP]

The stock exhaust cat back diameter is not a restriction on a 5.3, you won't outflow that.

 

A new aftermarket muffler from like dynomax/magnaflow etc etc is going to be way smaller than the trash can sized stock muffler so you would have to get another piece of pipe to connect it all back up again. The stock size is about 2.75 give or take so a 3in would slip over it but personally I wouldn't want to clamp it on there. I'd have the muffler welded in place.

 

Or just do a catback system. My full dynomax catback was $350 a few years ago on my 2012, they also had a mail in rebate for $50 at the time too.

[Mikebtte]

Yes,

The stock pipe will work for what you have, as talked about above the 3" will slide over the factory pipe.

You can get any 3" inlet muffler with an outlet you like and it will install easy.

Welding is an easy task in this set up and would cost little to have done.

Clamp on would also work but if you are keeping it for the Long haul, get it welded.

Also many cat back options available, they will be better but only by a small amount as they mearly replace the 2-3' of 2.75" pipe with 3" and for your application you will not notice the difference without headers and downpipes.

[Gooseslayer717]

On 10/30/2019 at 8:12 AM, Mikebtte said:

Yes,

The stock pipe will work for what you have, as talked about above the 3" will slide over the factory pipe.

You can get any 3" inlet muffler with an outlet you like and it will install easy.

Welding is an easy task in this set up and would cost little to have done.

Clamp on would also work but if you are keeping it for the Long haul, get it welded.

Also many cat back options available, they will be better but only by a small amount as they mearly replace the 2-3' of 2.75" pipe with 3" and for your application you will not notice the difference without headers and downpipes.

The original plan was to do LT Headers and Full Exhaust but after watching videos on installing headers i decided my DD didnt need that type of modification haha. I enjoy doing it myself so i would want to install the exhuast but the more i read into it welding is difficult when it is still on the truck and the process to get the exhaust back in as one piece seems difficult.

[Mikebtte]

7 hours ago, Gooseslayer717 said:

The original plan was to do LT Headers and Full Exhaust but after watching videos on installing headers i decided my DD didnt need that type of modification haha. I enjoy doing it myself so i would want to install the exhuast but the more i read into it welding is difficult when it is still on the truck and the process to get the exhaust back in as one piece seems difficult.

It is a little difficult to weld the top part of a muffler while the truck is on the ground, but it can be done. You could also find a shop to replace it at reasonable price and most will do whatever you want without question.