Hi all,

I've watched loads of videos of people who have removed secondary cats and or resonators. To me, personally, a lot sound really raspy and un-refined, more like a shouting car rather than a deep rumbling puuurrrrr.

I just watched this video, I think, going from description, guy has just removed his primary cats and left the rest, sounds really nice, same noise, just deeper, see here:



My Eurocharged tuner here in the UK says primary cat's give much better gains over removing secondary in comparison as they are pretty hefty, who else has just removed primary but left everything else completely stock? If it sounds like the above I am doing it!

I had straight pipes on my SL55 from the primary cats onwards, sounded fun for about 2 days then I hated it, was completely insane I'm getting older and want to retain the nice sound AMG built, just with a bit more ommpphhhhh

M

I have been looking in to this also,
Seems that the only way to do it is Headers, Cats, then mid pipes to the resonators and leave everything else.

Unless you could find a shop to make a pipe from your manifolds to the secondary cats?

It may be an option, but the issue of having a raspy exhaust tone after the cat removals can be remedied by a quality cat back. I don't have the rasp with my Eisenmann cat back with the secondary and resonator removed. Its very controlled compared to the stock cat back.


Im curious to see if we can benefit from simply removing the primary cats. May be less labor intensive compared to a full LTH setup.

Would love to know the same as I want that sound but not for £2500 fitted for headers haha


Did you get a price from MSL to do the work?


Think the below also has primary cats removed





Also just found this and he has more videos on his you tube, this is 2nd cat delete and the resonator delete behind the 2nd cats (I think that sounds pretty good)

I just removed my secondary cats... sounds great from outside the car. Still the original AMG sound, just a little bit louder and aggressive. Not raspy at all.

I was scared that it would be to loud, but after 2 days I'm already considering to delete the resonator also :-)

When driving with the windows closed in C-mode, normal driving, you can't tell the difference inside the car. Stealth-mode!

If you remove the primary cats, you will need a remap! I would leave them alone. Don't judge the sound on some crappy youtube videos...

True re videos but it does give you some sort of idea.

I'm getting a remap after the work so no issue there.

That second video sounds raspy to me, first one sounds like everything has been removed lol!

I was thinking just unbolt from underneath the manifold & then cut the pipe after the primary cat's installing some straight pipe in place, I have a good fabricator. Or just gut the primary cats out, messy job but doable. Hmmmmm

Mapper said removal of primary will unleash some decent HP where as secondary / resonator is minimal. Not too fussed about gains, Eurocharged V5 map will make it pokey enough, just want that original C63 sound, just a bit louder.

Anyone actually done this mind before I butcher my exhaust

The guys at Eurocharged Canada recommend getting rid of the secondary cat and resonator whilst adding a custom H-pipe. They say it will keep that AMG sound but beef it up when in the higher revs.

Haven't done it yet though. If I go down that route, it would have to be next spring/summer.

For those who removed secondary cats, how did u do it?
Did you just go to an exhaust shop and get the replaced with straight pipes?