what would be the effect on performance and sound if you modified the exhaust to eliminate the catalytic converters?
It looks simple enough to cut the pipe on both ends and insert a straight pipe. This would be easily reversible when you went to sell it.
It is probably also possible to put a tee in before the converters with a removable cap (like the side exhaust systems on hot rods).
With the reduction in back pressure it would seem that more torque would appear at the rear wheels???
When I punch out the exhaust on a Harley, I know you have to modify the carb. What would you have to do here?
Interested in any feedback from someone who has messed with this type of thing.

 

1. We dont have Carb's. No modern Mercedes uses one.
2. Getting rid of cat's is illegal in California, and many other states, however you could go with a cat that has a smaller cell count.
3. You might free up some more power with a less restrictive exhaust on the 63.
4. Good lord its a CLS, not an SLR. Side exhausts would look gay on the CLS. Its a luxury car for crying out loud.

 

It would be worth a try to remove them and see what happens. On a new car like this you would never get busted on the legality issue since you don't have to smog it for like 4-5 years.
I have no idea what else you'd have to do but I am assuming that you might need an ECU adjustment to account for the change. Tell you what, you try it and let us know

 

Im willing to bet $100 you will get a CEL (check engine light) when you remove the Cats

 

Not to hijack the thread but ... Damn Kevin, That is a grip of cars.

2006 MBZ CLS55 Euro Delivery
2005 Fleetwood Southwind (Toy Hauler)
2004 Porsche Cayenne S
1999 Porsche 996 Cab
1999 Regal 1900 LSR
1988 BMW 325ic (Can't part with)
1969 Porsche 911 RS Replica (Race Car)

What are you starting a museum?

 

no I just can't let go of anything I buy

 

Just took off my cats and no check engine light. Kept one resanator. Car sounds great. Its a 550

 

Lifsgud2: did you have to make any non-exhaust adjustments when the cats came off?
I know this is judgemental but how much louder is it, say at idle, or on the highway or when you down shift?
What did you do, cut them out and weld in a straight pipe?
You said you left one resonator. What was the original exhaust config?
Did you have a muffler shop do it or a customizer?

thanks. I'd love to hear it!!!

 

Keep in mind, he did a 550, not the AMG exhaust.

 

The car has two cats right underneath the gear shift. and a resanator. We cut the two cats out and added an X pipe in place. New mufflers were put in place. The sound is excellent...Not too loud and at idle you dont even here it. Only when you get on it around 2K RPM does it start to sound deep throaty. At 6K it almost sounds like A 63 or a 55. Yes my car is a 550. I will take some pics when the car is up in the air this weekend and show you what exactly they did.