EVO///AMG

Are there 4 or 2? I noticed when I had my exhaust put on that the there appeared to be 2 sets of cats...can the ones underneath the car be removed? I don't see any O2 sensors plugged into the cats underneath the car...so I'm guessing it should not trip the check engine light. Anyone know for sure?

Thanks

Mach430

From what I've been told, no you can not touch them without causing o2 sensor problems. Also, the 55 already has performance cats, and you really don't gain much by changing them.

bodyart27

pics of exhaust from when I had my 55 up on the dyno

bodyart27

one more

JamE55

Nice!

EVO///AMG

Thanks for the pic...so in answer to my question, are these cats or more resonators? I already took off the long resonator, but the car is still very quiet.

Blue Benz

What your question mark is by, I think those are the Cats.

Mach430

There is only one resonator, so you go it. I guess your next step is to get an exhaust system.

Norm C32

EVO///AMG, there are pup cats near the engine for quicker light-off due to emissions and main or secondary cats. You could remove the main/secondary cats and use a oxygen sensor spoof as the computer will know that the cats are not there.

The O2 spoofs go for about $100 a pair.

Norm

Mr. Vanos

Yes, there are 2 sets of cats on the car. The pair that are visible near the resonator and another set up by the manifold where the 02/lambda sensors plug into. We have removed the two cats furthest back on a few cars and run a bypass to the muffler (also eliminating the resonator) and the car sound really nice! However, I don't think it's worth it. If you remove the resonator and replace the muffler, you can achieve just as nice sound. The stock muffler is VERY quiet as well. If you want to replace the cats, get sport cats (we carry the MKB ones, but $$). Not only are they better sounding, but greatly help performance. Otherwise, keep what you have.

bodyart27

I think you might be able to see what mr Vanos is referring to here - right where the exhaust drops below the car - see the A-arms on each side in black for reference?

CLK55AMG

What if I just remove the resonator on my CLK55? The 55 has a different muffler than the 430, right? Will the 55 sound better with just the resonatore removed???
Dave