As far as I know, It Should Not. I Would check with the Dealer first though.

 

I put duals on mine and my service writer was drooling all on it so I guess it's ok with them yours could be different.

 

Depending on your dealer anything could void your warranty.....

 

You put Gas in the tank??,Some of them are ridiculous good thing this is America go around the bend to the one you like.

 

A few years ago, I installed a Magnaflow straight through muffler in place of the stock one. Dyno tested both. Pic below.

If the picture isn't clear enough, the red line is stock and blue is Magnaflow.

Magnaflow resulted in a whopping 0.21 HP gain!

So much for the BS of the "restrictive stock muffler" folks!

 

Thanks for the input. Mine Is Fine with Me, has the sound I was looking for. Maybe your comment will help some others decide if this is best for Them.

 

I myself could care Less about claims of HP gains by manufacturers.

I bought my K&N airfilter box NOT because of so called 9HP gains, I bought it because it LOOKS much better than that butt ugly stock air filter unit Chevy put on.

Same basic premis would apply to a Muffler purchase, Not because of any HP gains, but Mainly just to get a far Better SOUND out of it over the stock oem muffler.

I think that most would say about the same. I sure would not waste my time or money getting it Dyno tested to see what it actually got.

 

Yep, sound is one issue, as is gas mileage (not gonna comment on that now!).

But performance is another and this dyno proves that! Nobody else has ever done that.

Actually, the OEM muffler is pretty dang efficient. I think I have a cut-away pic in my gallery. Really, this surprised me and prompted me to take the cut off saw to the OEM to figure out why it was efficient and quiet at the same time. Go figger!?!

My issue is that, especially after having gone boosted (dyno was done while still NA), is to go for a a good flowing exhaust and keeping it as quiet as possible. With our wagon body, noise in the back is in the cabin. Been through a few setups and had a few surprises and disappointments, too!

But PLEASE don't claim that any muffler will increase power without having documentable proof.

 

Maybe it IS Just Me, But it Does Seem to improve the HP & MPG, Either way, It Still sounds Better than the Stock. If it works for Me, then I'm Happy. Like I mentioned before, To each their own, & Do what makes You happy with Anytype of modifications. Remember it is You that Owns it & has to be Happy, Not Anyone else. If someone else doesn't like it, They can go buy one & do what they want instead of being 'jealous' of Your HHR!

 

Sorry, I Did Not Want to give Anyone the Wrong impression on the HP or MPG! My Intensions were to just Give an Opinion. If there was Any offenses, NONE was Intended! I Don't Have documented Proof, I guess That is something that May differ from one to another.