Factory decat pipe.

[e500.org]

Hello all - after struggling to locate an exhaust front section with cats in good condition, I am considering replacing the existing hack-job decat pipe with a genuine decat pipe from MB.

My current setup is the original front section where someone has cut out the factory cats and welded pipes in. Unsightly to an otherwise quite clean underside.

I know 500Es in some markets were delivered with the factory decat (I've seen photos on here but can't find them, possibly posted by Dave). I believe this was on 1991/1992 cars. Mine is a 1991 so might be appropriate.

Can anyone point me in the direction of this unit and the corresponding part number? I wonder if it's NLA like the factory cats?

I have replaced the backbox and the resonator with stainless steel items from Fox and this is the final piece of the puzzle. I would assume this decat pipe however would not be stainless steel from Mercedes.

Many thanks all!

Cheers,
Bill

 

[e500.org]

Also forgot to add - I assume the original decat pipe would have provision for the oxygen sensor? TIA!

 

[gsxr]

MB Classic says it's available, but whooo, they are proud of that pipe. €1153 with VAT:
https://partssearch.mercedes-benz-classic.com/parts/A1244901920?tt=automatic

Photos here: http://www.w124performance.com/images/M119/exhaust/500E_non-cat_exhaust/

It does NOT have provision for the O2 sensor, but you can weld this in.

 

[e500.org]

MB Classic says it's available, but whooo, they are proud of that pipe. €1153 with VAT:
https://partssearch.mercedes-benz-classic.com/parts/A1244901920?tt=automatic

Photos here: http://www.w124performance.com/images/M119/exhaust/500E_non-cat_exhaust/

It does NOT have provision for the O2 sensor, but you can weld this in.

Thanks Dave that is exactly what I was looking for. Woah they're quite spendy but I'll try and locate one at lower cost. Why did decatted 500Es run without an o2 sensor? Would it be easy to weld one in, I would have thought there is a specific slot for the MB o2 sensor to plug into.

Also there is a unit in the engine room written "KAT" - i am not sure of the technical term. Would this also need replacing with the unit built for cars without a catalytic converter?

 

[195910]

Not worth it mate, just weld in the O2 sensor.

 

[gsxr]

Thanks Dave that is exactly what I was looking for. Woah they're quite spendy but I'll try and locate one at lower cost. Why did decatted 500Es run without an o2 sensor? Would it be easy to weld one in, I would have thought there is a specific slot for the MB o2 sensor to plug into.

AFAIK, it's more trouble than it's worth to try and convert to non-catalyst operation... would need a non-KAT trim plug at least, and possibly an older non-KAT LH module. Can't remember anyone who has done this. The simple solution is to weld in the O2 fitting and be done with it. Since the O2 sensor is pre-cat, it doesn't know if the cats are there or not.

 

[Eno]

I have been told there was MB doc/instruction in the early 90’s to “trick” the LH unit regarding removing KAT.

 

[gsxr]

There is a factory procedure to convert from non-KAT to catalyst (click here), but I've never seen the reverse. I'd prefer to have the closed-loop operation anyway, rather than a manual setting. I wonder what the trick does...