2015 Mercedes-AMG C63S Secondary Cat Delete
 

Damn the secondary cat delete made quite the difference! It sounds extremely good when revving the car, or driving it in the city, but at highway speeds/high revs it sounds ever better!

Cold start video! (Ignore my dads loud breathing lol)-

Revving video!-

That sounds so good, that's how it should have came from the factory. Is it any louder in the cabin?

Sounds great! What was the cost to do that? And is there any downside to this mod?

Only negative effect of an exhaust mod would be drop in MPG due to keeping your foot on the throttle all day long to hear it.

This is the essentially the same as a Mid-Pipe; correct?

finally a video on an exhaust modification, these type of videos makes me want to get one of these :zoom:

Well it already came from the factory without a resonator, and it already has cutouts which partially bypass the muffler so AMG already did a lot that you'd usually have to remove on your own for most cars.

In comfort mode it's still quiet, and luxurious. You just hear a tiny bit of that V8 rumble (More aggressive rumble then before). In Sport+ and Race mode it is quite a bit louder if you give the car gas, and the car makes popping and crackling and all those lovely sounds a lot more. So it's definitely louder in the cabin. Especially at the 4k and above rpm range. Also the best sound is in 5th gear when you're going 110km/h and you accelerate. Sounds so beastly during that!

$300 Canadian since it had two secondary cats instead of 1. Only downside is you lose a bit of backpressure therefore you lose some power at the lower range (It's so miniscule you don't even notice), but in return you get a lot more sound, and you get more power at the higher rpm range. To avoid the loss of backpressure though you can get xpipes instead of straight pipes, but you'd get a bit less sound then.

Haha true! Only other possible negative is that the neighbors will hate you, that is if you care what they think lol.

I believe it's similar since most aftermarket mid pipes get rid of the secondary cat, and the resonator.

The car sounds amazing stock, but this makes it sound a lot better! Still thinking of getting a exhaust cut out that fully bypasses the mufflers instead of partially bypassing them like the stock ones do, but I think that could possibly make the car a bit too loud.

One more question - does this mod negatively impact manufacturer warranty or annual emission check?

I believe it impacts the exhaust or the catalytic warranty. Dealership said not worry though since as long as you don't loose to much backpressure you're fine since it won't cause any damage to anything. As for the emissions... It coulda affect that since the secondary cat cleans a tiny bit of the emissions (5% if I remember correctly), but you won't get a check engine light since the emission sensor are before the secondary cat.

do you have the performance exhaust or the regular exhaust?

Performance exhaust

Where are the secondary cats?

It's just a bit after the sensor after the primary cat. Don't have a exact location though.

Is it on the down pipe? or is it on the mid pipe?

I believe that the secondary cats are on the mid pipe, while the Primary cat is just after the downpipe or at the downpipe.

Alright thats good to hear. Thanks

The sound that a decated C63S makes when upshifting at 6500-7000 rpm is absolutely insane!!!!

Post more videos!

I'll probably record a video or two on Friday when I'm hanging out with my friends, and probably post the video/videos on Friday night or Saturday morning.

Sounds great, might have to look into doing this to mine too!

Getting mine done tomorrow morning! I'll take some videos asap

The phone doesn't pick up the sound too well, and the videos don't do the sound justice at all but here are two anyways. If I ever get my hands on a go pro or borrow one from a friend then i'll make a gopro video. Hopefully that would pick up the sound properly cause there's a huge difference between stock, and secondary cat delete.

This seems like it's really illegal in Canada. You won't pass visual smog inspection in California. The only way to avoid it is if the car is so low that the guy can't tell. I'm talking like under 4" off the ground. They don't have lifts at the smog check places.

I believe that each province has it's own sets of laws so I'm safe here in Alberta especially since they don't check for emissions here.