Ss exhaust on a i6?

[mntb]

Yesterday a hole broke through the casing on the muffler of my Envoy. It's on the bottom near the rear of the muffler. And it's LOUD! and it sounds like a beefy civic. It's kind of embarrassing.
My cat back is kind of rusty. So I thought maybe replacing it with this cat back or one from the junkyard would be an option. My resonator was cut off by the previous owner.
Is there a difference between the i6 swb and ss swb cat back exhaust systems (pipe size, muffler, etc)?
I need to fix this ASAP and on the cheap. I just got the Envoy a week ago and it needs a few other issues worked out as well.

An exhaust shop wants $240 to install a factory replacement muffler.

I found a factory cat back from an trailblazer ss for $100. It's been cut behind the muffler during removal, but can be clamled/welded back together. There is hardly any rust on it. I was going to just cut the resonator off and call it Good for now.

Any thoughts or advice is greatly appreciated as always.

 

[therealsethallen]

While the system uses the same muffler, I'd try to find one that's not hacked. If you want something throaty without drone try a Magnaflow 12579 without a resonator.

If not, $90 for an OE Walker and have it installed locally, no shop should charge more than two hours for an exhaust.

 

[Mooseman]

I installed 3 different mufflers on my EXT 4.2 and it was horrible. The drone was maddening and it sounded like a fat ricer.

Aftermarket muffler comparison

Only thing that thread doesn't say is that the Magnaflow eventually became loud too with drone. Glad that truck is gone now but that exhaust will be going onto the Saab, which should sound awesome with a real V8. Most I'll do is hack off the resonator on my new '07 LS.

 

[mntb]

I might just try to get a cat back from a parts tb/envoy/etc. Looking at mine, I'll end up replacing the rest of it when it falls off in a year or so anyway (I love the Minnesota salt). Thats depending on what else I find here in the next few days.

The ss exhaust kind of bummed me out a little. It looks to be in pretty decent shape. I just wished he would have cut it behind the resonator. As I would hack that off anyway.

I was going to look at a company called Heartthrob exhaust. They are based in Litchfield, MN. I first heard of them on the at gearz show with that Stacey guy.

Has anyone had a tough time finding a shop to do something like duals or just adding a muffler like a MagnaFlow to their tb/envoy 4.2l? Every shop I have talked to have sounded reluctant to even quiet a ball park price. Like they don't want to even attempt the job.

I have noticed a few members go from stock to aftermarket/louder to stock minus the resonator exhaust setups.

Thanks for the replies

 

[mntb]

Has anyone used the walker mufflers? Orielly's has a walker soundfx muffler for $46.
Might be an option. The soundfx is supposed to be louder than stock I think. I just don't know how it would sound. I looked on youtube but didn't find any on an 4.2l i6. I would probably just clamp it in for now.

 

[littleblazer]

The dual is a waste on the 4.2 really, it all collects down at the manifold and then shoots out the back. There may be zero performance gain with that. Maybe even a reduction because of the added weight. I also don't think the hangers are there for the dual so it would have to be fabricated into place. Also it is simply an aesthetic mod.

The walker soundfx as I have been told (or know) is essentially a slightly louder stock replacement. Take that for what its worth.

 

[mntb]

Is the stock cat back system pretty restrictive? Or is it like the 3.8l Grand prix's/regals/etc where the exhaust manifolds are the major restriction in that exhaust system?

I figured there was no gain for duals, just looks. Especially from a I6. I simply think it looks odd to only have one tailpipe sticking out the back. I like a balanced look. And I really like the looks of the exhaust coming out behind the back wheels. Like I have seen a few members have here.
But beggars can't be choosers and my envoy will never be a show stopper or winner. At this point I'll take what I can get. I just want to keep the performance at stock level, or better yet increase it a little. I can't stand the way it sounds and vibrates the floor boards.
The only way I can see it being any louder is with open exhaust manifolds.

 

[littleblazer]

The 07-09 manifolds are a bit better but overall the stock exhaust isn't too bad.

 

[mrwitty_1]

On my previous 02 SWB Envoy I had trouble finding a exhaust system that fit the factory system. The exhaust was 3 inch all the way to the resonator then it was 2-1/2 inlet. matched a Walker 3 inch inlet 3 inch outlet muffler with same shell length and no drone.

 

[Mooseman]

The original stock system is pretty free flowing. Walker mufflers are supposedly necked down inside from 2.75" to 2.5" so you would lose some flow. There is a stainless system for the 4.2 that is 3" from the cat back but is stupid loud and annoying with its drone.

I would look for a shop to custom build a cat back using 3" pipe and use your choice of 3" muffler. Only problem is I tried 3 different ones (JBA, Dynomax VT and Magnaflow) and they all sounded like a ratted out Honda. Just the nature of the inline engine I guess.