Muffler Help needed

[Ahenley18]

Hello, I have a 1999 GMC Yukon and I recentely purchased a flowmaster 40 series muffler off of amazon. BOTH amazon and the flowmaster website said this muffler would fit my yukon and I am wondering if this is true, if not what should I do?

http://www.amazon.com/Flowmaster-43...GMC|48&Year=1999|1999&vehicleType=6&carId=001

 

[95escahoe]

Hello, I have a 1999 GMC Yukon and I recentely purchased a flowmaster 40 series muffler off of amazon. BOTH amazon and the flowmaster website said this muffler would fit my yukon and I am wondering if this is true, if not what should I do?

http://www.amazon.com/Flowmaster-43...GMC|48&Year=1999|1999&vehicleType=6&carId=001

should fit I run a 3in inlet and outlet muffler on my 95 Tahoe and fits fine, that is the correct size Flowmaster stated for my year use a different brand muffler tho

 

[TigerEyz3]

Hello, I have a 1999 GMC Yukon and I recentely purchased a flowmaster 40 series muffler off of amazon. BOTH amazon and the flowmaster website said this muffler would fit my yukon and I am wondering if this is true, if not what should I do?

http://www.amazon.com/Flowmaster-43043-40-Muffler-Aggressive/dp/B000QJG1AS/ref=au_pf_pfg_s?ie=UTF8&Model=Yukon|558&n=15684181&s=automotive&Make=GMC|48&Year=1999|1999&vehicleType=6&carId=001

Typically, a single-inlet/single-outlet (SI/SO) muffler will NOT fit a stock 1999 Tahoe/Yukon unless the stock system is modified with a Y-pipe. In stock form, most 1999s came with a 2" dual-inlet/2.75" single-outlet (DI/SO) arrangement. It's common to install 2.25" or 2.5" dual piping instead of the restrictive factory setup.

If you've already ordered the SI/SO muffler, you have a few options:

1. return it
2. y-pipe your system to accept it - most any muffler shop can handle this task
3. sell it and purchase a DI/SO muffler of your choice that is designed for your application

Clarification: some Tahoes/Yukons did come with the SI/SO arrangement, most 1999 4dr models had the DI/SO configuration though. For future reference, it's best to look under your rig to see what you need before ordering.

Here's a LINK to the cat-back that I have on my rig... DI/SO (centered outlet)

 

[Ahenley18]

thanks for the help, I think ill go along the y-pipe path, that way I dont have to reship the muffler back to amazon. I could just buy a y-pipe online right? I would think it would be cheaper.

 

[ezdaar]

cal speed headers, go for it, get the Y pipe and headers!
They wont be in stock long.

 

[steamroller]

Unless you're collecting exhaust parts for another vehicle all together, a 99 is still an OBS so those headers linked won't fit.

 

[992dr]

It would be easier to get the right muffler. Couldnt you get a call tag from Amazon for free return shipping?

ez,
Those headers and Y-pipe are pretty nice but, they're for a NBS Silverados with a 5.3.

 

[ezdaar]

Some 99's have the 5.3 in it aswell.

 

[TigerEyz3]

Not the Tahoe/Yukon, unless an engine swap was done... The LS motor (4.8/5.3) wasn't used in the Tahoe/Yukon/Sub until the 2000 model year (not counting the 2000 Limited Tahoe/Yukons which still had the 5.7L).

The 1999 model year for the trucks used the 4.8/5.3/6.0 motor... the headers were likely used on that rather than the Tahoe/Yukon/Sub.

 

[19Yukon97]

The only Flowmasters that fit on the 96-99 Yuks,tahoes, and burbs is the 70 series big block mufflers. Everything else has to be modified. I run Pacesetter longtube headers with armor coat, 3 inch piping with new magnaflow cats, and a single in single out 50 series delta flow, with 3 inch piping out the stock location with a 3 inch to 4.5 inch tip.

---------- Post added at 03:13 PM ---------- Previous post was at 03:08 PM ----------

I forgot to add this...
oh you can get an excellently made magnaflow y-pipe for 25$ off of amazon. Just measure your inlet pipes and get the right one. I still run the stock setup with the piping and everything. I mean with the dual in/single out setup. Just running a dual 3 inch in/3 inch out y-pipe.
Heres the link for the y-pipe...
http://www.amazon.com/Magnaflow-107..._1?s=automotive&ie=UTF8&qid=1327691540&sr=1-1