This is a 2011 MCS with an Akrapovic DP and 2nd Cat delete. Everything else is stock. I'm pretty happy with it, zero drone ever, there's actually a power gain, and much cheaper than doing a full turbo back exhaust.

I tried to remove the resonator but I drove maybe 100 yards without it and immediately turned around to have it put back on. The car was way, way too loud and almost embarrassing.

Now it has a pretty decent note, is loud under heavy-ish acceleration, but quiet when cruising or slowly accelerating. The pops and burbles sound better too, it's almost like the car is spitting instead of just a loud pop.

Excuse the slow start, I had 4 wheels/tires in the back seats and the car was much, much heavier than I'm used to.

 

Damn! That sounds great. Wonder what putting a Magnaflow muffler on it would do to the sound overall.

 

That's what i didn't get to hear that day i drove your car Sounds nice!

 

That does sound pretty good.

 

Sounds really nice! Jealous of that P&B sound.

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Nicee!!!!

 

That DOES sound sweet!!!

 

Cal, or anybody else who knows, when the shop removes the 2nd cat I'm assuming they weld in replacement straight pipe. Is this the case and can it cause problems (not emissions testing related), ie rust?
Thanks again.

 

Glad everyone likes it. Removing that 2nd cat made an enormous difference in the sound.

The guy at the shop I went to said removing it wouldn't do anything sound-wise or power-wise. He also said that I did the exhaust in reverse by doing the DP first and that a DP wouldn't give you any gains. I should have known right there that he didn't really know what he was talking about. He must be used to kids bringing in their '98 civic to put a 4" muffler on for "power gains".

 

Yes, that's what they do.

You can have them install an aluminum pipe which won't rust. At that point it's just as tough as the OEM parts. Just make sure the shop you go to knows what their doing so you don't have any leaks and the weld is solid. I'm not to worried about rust where I live but I know most of the country has to deal with winter and salt on the road.

 

HA!!! I live in Savannah Georgia. Most people here can't even spell "snow"!

You are making my decision easier.

 

Do it! You'll be so glad you did. It also makes you eligible for the stage II NM tune.

 

What you could do in states that require emission testing is just have them make you a test pipe. So that you can swap it in and out as needed.

 

So stock MCS, second cat delete, and a DP creates that?! Sold.

 

Not to confuse anyone but isn't there just one cat on our cars? Don't people mean the resonator?

 

The exhaust is as follows:
-Downpipe, which contains the main (monitored) cat, comes out of turbo.
-About 2' of pipe.
-2nd Cat (which is unmonitored meaning there are no O2 sensors seeing it).
-Resonator (kind of like a pre-muffler)
-Muffler
-Tailpipes


The JCW cars are the same except they do not have a 2nd cat. If you look under your car, under where the center armrest would be, you will see the 2nd cat followed by the resonator.

 

Strange my 11' MCS didn't have that extra cat. Just dp/cat(monitored), resonator, muffler and tailpipes.

 

Hmm, that is strange unless you have the JCW exhaust. I think you need to post a pic, I don't believe you

 

Lol too late for pics. I noticed it when I was getting my custom magnaflow done a while ago. He just went right from the dp flange straight to the magnaflow muffler. The part he removed had only one resonator and when I look under there now there's no 2nd cat.

 

Sounds great...now for the other part: Have you had this set up pass smog in CA?

 

CA owners pay a smog abatement fee for cars less than 6 model years old, so he wouldn't have to smog until 2017

 

Would removing the 2nd cat cause a CEL?

 

^ nope, it will not. everything after that is not "monitored".

 

Sounds superb!