ydlee

Plan on doing delete of resonator and install of a universal xpipe but the universal xpipes are about 12" long and you still need to get extended piping welded to connect to the mufflers. I was thinking instead of getting a short 12" xpipe, get an xpipe that is already long and have it cut and welded to right length? This way you would only need two welds on each on the connecting pipes to the mufflers. I was thinking an 2.5" diameter xpipe off C6 corvette? And the same would go for an CLS55 or 63 with 3" piping from a C6 Z06 Corvette as well. Any input or advice would be appreciated.

Pic of stock C6 Corvette x pipe long in length
Pic of aftermarket B&B C6 Corvette x pipe
Pics from another forum member that did this mod on their CLS before and after the magnaflow
x pipe installed but as you can see extended pipes are needed to be welded on both ends to connect to mufflers
pic of magnaflow 12" x pipe
Pic of summit racing chevy universal x pipe

Half Fast Drivr

Let me start by clearly stating, I am no expert on this. I am only going by what I've read here and on other forums. I only offer these comments because I too was considering this 'mod'.

The CLS' resonator is in effect, an X-Pipe. There is NO need to delete. Further, the CLS has the best flowing and sounding mufflers of all current MB's. Look forwards, not backwards. If one wishes to decrease exhaust restriction, or just improve the sound, secondary cat delete is far more appropriate and productive than an X-pipe. Beyond that, shorty headers or even better, long tubes are the answer.

Arguments can be made about the sound differences between OEM, X, H and other type pipes, but they all seem to lead to nowhere. I've found there are proponents of every type in equal numbers, arguing both ways, effectively canceling each other out more than they claim the mod may or may not. At that point I asked myself, do I want to throw money at something that may barely be noticeable? And if noticeable, only at wide open throttle?

Secondary cat = two birds, one stone.
Headers = 3 or 4 birds... and a few ponies too!

Sorry this post did not address your specific question, but hopefully it answered a bigger one for you. Again, I am NO expert, only reflecting what I've gathered. Now, anybody got an inexpensive set of headers for me?

ydlee

Removing secondary resonators on cats will it cause check engine light and will it pass smog?

GuestFromTampa

Any update ?

miraclewhip_cls

I believe no code error with secondary cats removed but will get code error when you delete the resonator. the above description is the way I am going removing secondary's