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MB might offer rebuilt cats and for a reasonable price.
You can replace with modern cats, not too hard to do (I had someone swap them out). The car will throw a light if you don't have cats. (I assume you have 4 sensors) the front O2 sensors are for tuning the fuel mixture, while the rear ones check the effectiveness of the cats. There used to be sensor substitutes for cat delete off-road usage that provided fake values to the computer, but I don't think they exist any more. V8 and 6 cylinder cars use small cats, so its easier to do, but the V12 cars need big cats because 1 cat serves 6 cylinders instead of 4 or 3. The initial replacement cats for my car were rated for a V8 (2 x 4 cylinder usage) and were too small.
I had mine replaced with modern new cats instead of the old style ceramic design MB originally employed. After the new cats were installed the sound of the exhaust changed slightly, but everything works and there are no CEL events. New style cats should flow better than original and aren't really a hindrance to performance like in the olden days.
The V12 cat swap was about $500, your's should be a little less.
Last year I got fed up with the aftermarket replacement cats and ordered new MB ones. Not terribly expensive, and they wanted my old cats (the whole middle cat pipes). You get a refund of $200 per pipe which helps offset the overall price of the replacements.
2 new (not rebuilt) factory cat pipes for the V12.
The paperwork showing the refund and the prices circa last year.
Who know how much it would cost now with the "for our own green good" inflation.
MB might offer rebuilt cats and for a reasonable price.
You can replace with modern cats, not too hard to do (I had someone swap them out). The car will throw a light if you don't have cats. (I assume you have 4 sensors) the front O2 sensors are for tuning the fuel mixture, while the rear ones check the effectiveness of the cats. There used to be sensor substitutes for cat delete off-road usage that provided fake values to the computer, but I don't think they exist any more. V8 and 6 cylinder cars use small cats, so its easier to do, but the V12 cars need big cats because 1 cat serves 6 cylinders instead of 4 or 3. The initial replacement cats for my car were rated for a V8 (2 x 4 cylinder usage) and were too small.
I had mine replaced with modern new cats instead of the old style ceramic design MB originally employed. After the new cats were installed the sound of the exhaust changed slightly, but everything works and there are no CEL events. New style cats should flow better than original and aren't really a hindrance to performance like in the olden days.
The V12 cat swap was about $500, your's should be a little less.
You need to have primary cats to avoid check engine light. Secondaries can stay gone but you can smell their non existence lol especially with top down. Buy magnaflows they come from ca in the us. They work great
The state of Colorado applied a law that requires CARB compliant cats. Twice the price of a free flow aftermarket cat and if they do a mirror test at emissions center it better have the CARB numbers. With all the cat thefts its costing a fortune for victims to replace cats.
I don't actually know which brand of cat the exhaust guy used, but I did look down into the cat's inlets before they were welded. They weren't the brick style, but a grid.
Ultimately, the fit and sound got on my nerves and after about 8 years, I reverted to OEM MB replacements that looked absolutely brand new.
You wanted to build you a SL55 ;-)
And if you contact Drexler in Germany they can build you the diff with 2.82 ratio. (As it is for the SL55) but then you need new software on the EGS too.
Ahmed, I know it sounds odd, but have you tried the dealership?
I changed out my original cats for aftermarket ones 8 years ago and they never fit or worked right. They hung too low and occasionally threw CELs.
Last year I went to the dealership and was surprised to find out that brand new (but priced as reconditioned) cats were available. The two cat pipes are new right down to the shielding. The OEM cats are triangular on the V12 out of necessity and sound better than the aftermarket Magnaflows.
They weren't that costly and the fit and performance is OEM.
After I got the cats, I found part numbers for V12 AMG cats. I don't know what the difference was, but there might be factory AMG cats available for you. After getting a core of $200 for each old cat (even though mine were modded), the new cats came out to $260 and $334. I know they will last 200K miles.
Hello everyone, just an update.
The dealer no longer carries these parts unfortunately, so I went ahead and did 2 things:
1. Ordered universal cats from Magnaflow ( which should easily replace the undercarriage secondary ones )
2. I also took the plunge and went ahead with ordering the BM Catalysts complete system which includes primary and secondary cats. As per the item specifications and description, they should fit the 1998 to 2001 R129 V6's and V8's M113 setup.
The only observation I may have is that these "might be" made for RHD drive cars ( no mention of this, so I might be making a big deal of it ), but I will go ahead and assume no difference. Even if there are, my exhaust shop will make them fit. The price was too good to pass on honestly. The BM part numbers are 90834 and 90835.
Hello everyone, just an updated.
The dealer no longer carries these parts unfortunately, so I went ahead and did 2 things:
1. Ordered universal cats from Magnaflow ( which should easily replace the undercarriage secondary ones )
2. I also took the plunge and went ahead with ordering the BM Catalysts complete system which includes primary and secondary cats. As per the item specifications and description, they should fit the 1998 to 2001 R129 V6's and V8's M113 setup.
The only observation I may have is that these "might be" made for RHD drive cars ( no mention of this, so I might be making a big deal of it ), but I will go ahead and assume no difference. Even if there are, my exhaust shop will make them fit. The price was too good to pass on honestly. The BM part numbers are 90834 and 90835.
Fingers crossed.
AWESOME !
after reading your whole 3 year long thread it’s great to see you got something for your baby. Let us know how it goes. I’m currently looking for a new exhaust on my 94 sl500, if u have any info I’d be more than appreciative.
-drew
08-29-2019, 03:09 AM
