DaSkorpion

The time has come for my cats to be replaced and I did reply to a few posts about after market W208 Catalytic Converters but have not received any responses back yet as those threads might have aged a bit much for anyone to pay any mind to.

Reason I'm starting a new thread specifically is to see who's purchased what and what are the feasible options out there for a 2002 CLK55.

There were some old ebay links in some of the previous threads but they all seem to be dead links now so I'd appreciate it if any of my comrades here can point me in the right direction.

DaSkorpion

Comrades...anyone, somebody: yes, no, maybe? I see the views but no replies.

MouTine

Are you talkking about original stock system?

I have Kleemann headers and secondary de-cat pipes. No cats at all. Need to dyno run it this summer at some point.

DaSkorpion

yes MouTine I'm still using the bone stock system and I have a CEL due to the cats going bad so I cannot pass state inspection. Would love to go with a high flow cat just not sure what works and does not throw any CELs. Definitely interested in secondary de-cat pipes but need the primary cats done asap.

Thanks for your feedback...very much appreciate it.

MouTine

So... Do you need to pass some emission limits or do you have visual inspection aswell? I mean could you just buy pair of Magnaflow cats and weld them where secondarys are now and relocate rear lambda / O2 sensors after them? And empty primaries? If not then you need to browse Ebay. =(

DaSkorpion

Both emissions and visual inspections. I've been looking at these on flee bay http://www.ebay.com/itm/310311079252?ru=http%3A%2F%2Fwww.ebay.com%2Fsch%2Fi.html%3F_sacat%3D0%26_from%3DR40%26_nkw%3D310311079252%26_rdc%3D1
I have emailed the seller and still waiting for him to respond back but from what I've read, recommendations are to go with a metallic substrate 300 cell hfc just not sure if I need a 2.5" or 3" and if these will suffice.

MouTine

Looks very good. If you just could fit them where primary cats are located now. Downpipes are 2,5".

MouTine

Btw... If you need a used set try to contact Kleemann Denmark. They should have my old original manifolds and primary cats. I totaly forget to pick them when I left in hurry after they installed SS manifolds and tune.

MarcusF

If you want to solve the problem of the CEL due to the cat not being within spec, buy a pair of doorman spark plug non-foulers. Screw the extension into the secondary O2 sensor port on the exhaust, then screw your O2 sensor into the extension. It moves the O2 sensor out of the exhaust stream and the light will go out. The fix is about $10 for both sides. I have them on my car and they work.


If you want high flow cats, Magnaflow metal substrate cats have substantially higher flow rates than your engine.

DaSkorpion

Thanks MarcusF!

Looks like I'd be going the Magnaflow route after all. Thanks to all who chipped in with inputs / ideas

romaneve

just had my 2001 clk55 serviced, for a check engine light. the computer registered a misfire in one of the cylinders and was caused by resistance in the spark plug wires (they replaced the spark plugs as part of the service). after replacing the spark plug wires, it kept registering a misfire at high rpms and they determined that it was the catalytic converter causing vacuum resulting in the misfire. does that sound feasible to anyone? apparently it's got a small dent in it, and needs to be replaced, so instead of spending $2700.00 on the replacement, I'm looking to go with an aftermarket replacement. any suggestions?

MarcusF

Cats can't cause vacuum. When busted (and a dent in the shell is a very strong sign) a cat can clog the exhaust which can result in a misfire and/or severe loss of power at high RPM.

Magnaflow and Random Technology make good units. You may want to purchase a metal substrate (metal core) unit.

romaneve

Thanks MarcusF, that is very helpful information.

benzslo

The primary cats have a bend built right into the outlet, will need some custom work to make a universal work. I'd look for a used set from clk55, clk430, or c43, should be plenty out there. I do have the stock cat pipes in the garage rafters from my low mileage c43 but would not let them go for cheap.

400HP55

Romaneve,

I bet one of your coil packs is corroded out...

The cats on mine went out. Failed smog. Couldn't find a pair for less than $1500. So then I figured something out. $125 dollars later passed smog no problem =D Oh, and I used 300 Cell cats which gave me some HP as well lol <--- California