-Moleman-

Ok, just got my 2016 C63s a few weeks ago and after reading the excellent topic on the subject decided to delete my secondary CAT's. Booked into a great guy here in NI yesterday and when he got my car on the ramps we discovered there were no secondary cats, just straight pipes running all the way back from the mufflers to the primary cats?! First instinct was previous owner has had them removed but the mechanic said he was almost certain it was like that from the factory, no signs of any mods, pipes all totally intact from front to back?!

very very strange, anyone heard of anything like this on UK 2016 cars? As a way of increasing the sound without going the full down pipe route we are going to replace the mufflers with a sports version instead...

AlexZTuned

Pics? I wouldn’t replace the muffler, unless you want to lose the AMG tone.

AV1

They've been removed for sure.

Must have been a very good job if it's not noticeable

-Moleman-

ill try to crawl underneath and get a few pics.

Interested on the muffler comment, when I asked for a bit more sound without going the down pipe route he suggested cutting out the muffler and then tacking in a few sport mufflers options in their place, he would let me hear the car on idle and on the throttle until I found the one I liked.

are you saying the distinctive amg gurgle could be lost by replacing the factory muffler?

-Moleman-

Ok, I took a few shots of the exhaust from the back of the car all the way to the front,

ezatnova

That’s not where they are. You have to look up.

-Moleman-

I thought they should have been somewhere between the second and third photo, the last photo shows the pipes just before they bend up towards the engine which is surely where the primary CAT’s are located?

its an entirely straight pipe from the tips and muffler at one end all the way until it disappears from sight up into the engine bay. They surely don’t have the primary and secondary CAT’s so close together up into the engine bay itself?

skim7x

If your mechanic can't even find the cats, I wouldn't trust them with the job haha..

Second, go look at the entire thread about secondary cats and you'll see where they are...

Edit: is that a non-perf exhaust?

-Moleman-

thats the point, he has done many, many secondary cat deletes and full system installs although mainly on M car, he also builds and rents out a fleet of track day cars again all M3’s. When we got underneath the car there are no cats where we expected to see them, when I suggested the previous owner had removed them he said it whole pipe looked original front to back, no mods in his opinion.

Its a non performance exhaust unfortunately

-Moleman-

If this is roughly where the secondary cats are on a w205 C63s then they are not there, that’s roughly the area between my second and third photo a few posts above.

AlexZTuned

That exhaust pic is from a W204. Here is the W205 diagram - the primary cats are right off the turbochargers (basically in engine bay), and secondaries at the end of the downpipe.

You’re looking at the wrong part, that’s the catback. We have separate downpipes that have both cats on them.

See #1 and #2 for the secondary cats. You posted pictures of #6.

-Moleman-

Very helpful, thanks very much