300SDL exhaust - PeachParts Mercedes-Benz Forum

sixto · #1 04-29-2003, 01:06 PM

I'd like to compare notes on what folks have for an exhaust system on their SDLs. I'll use this picture as a referece.

http://www.timevalve.com/cat/us/p15c.html

Mine exits the turbo, goes into something that looks like a catalytic converter that's too small for this size car, goes into something that looks like one of the two wing mufflers on a 126 SD or later 126 V8 (but it's inline), then goes to the rear muffler.

The middle muffler has an offset inlet and straight outlet. Looks like an MB part.

All the piping and fittings look original or at least factory quality.

Any idea what the first muffler is? Some sort of post turbo trap oxidizer?

Thanks,
Sixto
91 300SE
87 300SDL
83 300SD

airfoill · #2 04-29-2003, 01:30 PM

Sixto,

Mine is set up exactly the same way. I believe that first muffler is an actual catalytic converter that took place of the trap O. when the trap O. was replaced.

Herb
'82 240D
'87 300SDL
'92 300D 2.5 Turbo

virtualdoc07 · #3 04-29-2003, 01:56 PM

Actually, I own both 86 and an 87 the first "muffler" is a cat converter that cost between $500-800.00. I also put on replacement syemt from Timevalve on the 86'. Beside helping the environment the cat converter sure quiets down noise intrusion in the cabin on the 87'

gsxr · #4 04-29-2003, 03:12 PM

The first item, under the passenger seat approximately, is the oxidation catalyst. This is the replacement for the old trap oxidizer that used to be mounted above the turbo. And yes it does look too small for the engine, huh! The other two lumps are the center muffler and rear muffler.

I have wondered how much power, if any, would be gained by removing the first (small) catalyst and replacing it with the original straight pipe. I have heard that if you hollow it out, you do get more noise; perhaps from the empty housing acting like a resonance chamber? But I wouldn't expect that with a real replacement pipe; odd that Virtual Doc noticed more noise. One of these days I'll experiment with that.

On a side note, an MBZ.org list member recently had a big problem with his SDL running badly, and it turned out to be a plugged catalyst! Replacing it cured the problem.

#5 04-29-2003, 03:56 PM

I have a CA 300SDL.. I have two "trap oxidizers" under my car.

gsxr · #6 04-29-2003, 04:37 PM

No, you don't have two.

All 1987 300D's and 300SDL's had the trap oxidizer. This was replaced under recall with the oxidation catalyst. Either way you only have ONE cat, never two under any circumstances... CA or not!