Hey guys,
I have a CLK500 (yeah I know, not a 55, but thought I'd get some input here as well since the engines are almost the same). I have secondary cat/resonator/muffler delete with an X-pipe and quad tips. I want some more "oomph", but I feel that I'm just used to the sound of the exhaust. What could I do to make it louder? Would a primary cat delete do the trick or even high flow primary cats?
Any input would be appreciated. Thanks.

Here is my current exhaust setup on the dyno:

Headers!!

I'm in CA and headers are not smog-legal AFAIK

I don't know much about smog testing but I would have thought some custom mid lengths with good quality high flow primary cats would work well. May need secondary high flow cats put back in to accompany them?

Would it quiet the tone down on my current setup? I definitely don't want it quieter hahaha

Neither are any of the other modifications you have made.

Headers will not make your car quieter AND if you take your car to a state sponsored STAR station (like I'm forced to do), they won't check.

The car isn't even run during the test. It's a DAD OBD test. If the ECU is happy, so is the smog station. That said, if the smog station wants, they can send you to a referee, so you really want to blend in. Chromed or wrapped headers may draw unwanted attention. If they send you to a referee, the refs are a lot more thorough. They'll do a proper visual and your lack of secondaries will cause you to fail.

find a place you can pay off and get some high flow cats in place of your primaries

+h pipe instead of xpipe, make little less power but sounds a lot meaner

Marcus, hope all is well! Been some time

What brand high flow cats and part number would fit my car? I haven't found anything so far.

Things are going great. Thanks again for your OE springs. That comes up more often than you'd imagine. People ask and I tell them, "Those are Chappy's OE 208 AMG springs that no one would buy way back when" . Hope things are well for you as well. Do you still have your wagon too? That was a very clean car.

Kids are growing up fast! Boys are in 2nd and 4th grades now

The S124 went to a very good home and fellow forum member a few years ago. My daily has been an '11 E350 Sport since then....but desire to back to a wagon! I have one coming from your neck of the woods. Pics when this brute gets here.

I still have the CLK (up to 54k miles now lol)

Apologies to the OP for thread jack.

Just get your c63 man. Stop wasting money on that car. It's already obnoxiously loud.

I like the high flow cat idea along with an H pipe.

You could also go back stock and install some cut-outs from vivid racing. hmmm.