Guys, I'm going to remove the resonator on Wednesday and was thinking of pulling out the secondary cats as well. I don't want an X-Pipe as I like the raw, untamed sound the most. So basically I'll go with 2.75" straight pipes from Primaries all the way to the Mufflers.

Has anybody done this before?

Also, will it cause any emission problem? Will it pass emissions at all?

If any European members are reading this, if I was to send the car from Canada to Europe, will I pass the emissions with this set-up in Europe?

Thanks, I just don't want to pull out the resonator and then end up going in the second time to pull out the secondaries. Just want to do it in one shot!

Anybody?

Maybe this will help. I am not running any cats on my CLK 63 Black Series, but I am running X-pipe set up. I am also running resonators. I initially was running no cats and no resonators but it did not sound good. It had nothing to do with decibal levels it just sounded bad, raspy and un-tuned, so we decided to go back in and ad some high flow resonators, now it sounds great. There are several clips of my car on You Tube under "Evosport CLK Black Series" if you want to hear what it sounds like.

As for your emissions...no, I doubt it is ever going to pass if you proceed the way you described. First of all there is an exhaust sensor that you will need to replace or somehow over ride. If this is not done you will get an error code and/or "Check Engine" light on your dash. That alone will fail your car and not allow them to even go any further with an emmisions test. I'm not sure about the laws and proceedures where you live in, but even if you address the error code and o2/exhaust sensor issue most U.S. states do a visual inspection to see if cats are indeed in place. There are a few things you can do to pass a visual inspection. Take your stock cats, and hollow out the internals, and then run you straight tube through them, the other thing you can do is purchase a set of high flow cats.

Either way I would make sure you have a tuner or a shop very familar with M-B's do the work, the guys down at the local muffler shop are not gonna have a clue. I would also recomend going with an X-pipe rather than straight pipes.

Probaly not what you wanted to hear, but I hope it helps.

Thanks! I actually needed to hear something like this, to just take it easy and go with a simple resonator removal.

I though that there are no CO2 sensors ifnfront of the secondaries. On my E55 I removed both, but I did install an X-Pipe. I did not get any CELs. However I'm really unfamiliar with the exhaust set-up on the 63s.

i didnt think that the secondary cats had 02s. i was actually thinking about knocking mine out. anyone have first hand experience if it makes power or not????

I am not 100% sure - but I do not believe the Black Series has secondary cats. Just the primary cats behind the headers and then small resonators mounted midship.

was in reference to the OP, he had a CLS. i dont think MB uses an o2 downstream from the secondary cats. If there is nothing after them, you wont turn on any check engine lights if they are removed. physically removing them will fail a visual emissions inspection in NJ, not sure about other states or overseas.