I recently purchased catless downpipes for my C63S with the performance exhaust and it is obnoxiously loud and smelly.

I just purchased a set of catted downpipes from Mikes Custom fitted with GESI 7830 cats. It seemed like this was the way to go. I am still waiting for them to be shipped.

Wondering if anyone on here is running aftermarket sport cat downpipes with stock exhaust. Interested to see if the smell goes away and if they are quieter and less raspy than catless downpipes.

Not trying to waste any more money on the exhaust. I just wanted it to be a little louder than stock.

Below is a video of my exhaust with the catless downpipes.

 

Gesi Cats will definitely make the smell significantly more tolerable. Loudness will obviously be lower than a catless DP, but the GESI cats are extremely free flowing, so might not get rid of all the rasp but will sure reduce it. Will you mind sharing how much you are paying to have the custom DPs with the cats done? Also as far as I know, the gesi cats are more than enough to take care of the CEL, so you would not need a tune. But I guess you probably already got one if you have DPs?

 

@DKCRE OH man it sounds so good though!!

 

I just hope it will be reduced and more throaty. I think I paid $2700 for his custom DP's with the cats already welded in. The GESI cats aren't cheap. I think they are $400 a piece. I'm not sure if the GESI cats will eliminate the CEL because I believe they are after the O2 sensors. They are welded in on the straight 2nd piece of the DP. I should have my stage 1 DME tune today. I was originally going to go Stage 2 but I put a lot of miles on my vehicles and don't want to push this to the limit. I should be happy with the Stage 1 as it is already a massive gain and will take care of the CEL.

 

I have Gesi cats on Mikes DPs...let me tell you they're not much quieter than catless when in Sport+. Other modes are reasonable. No smell at all. You will get a Cel with the Gesi's. Dme stage 2 tune codes it out.

 

Do you have any videos of your exhaust with them on? Is there any rasp?

Are you satisfied with them as well or is it just too loud?

Sport mode sounds almost perfect but sport + is obnoxious lol.

 

I think what you want youll get from the AWE track exhaust.

 

Isn’t that louder than the stock performance exhaust?

 

There is a little bit of rasp, no where near as much as catless, and it's not annoyingly loud. If you go to Above and Beyond performance's Instagram page about 20 posts down there is a gray with black top c63. That's me, scroll to 2nd video (outdoors) for a sound clip. The 1st video is inside their garage which adds alot of metallic type sound which isn't representative of how it truly sounds. Wear headphones otherwise it sounds empty and not accurate through your phone or tablet.

 

yeah but the downpipes are louder too. downpipes = raspy sound but track exhaust = throaty sound which you said youd like.

 

I probably should have just bought the AWE exhaust before the downpipes to see. I didn't do enough research.