Removing cats on C32
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Joined: Apr 2008
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From: San Francisco, CA
W203 C32 AMG, W124 E300D
Removing cats on C32
Has anyone done it? While driving home one of the cats blew and i could hear the honeycomb falling apart and the pieces rattling inside the pipe as i rev the engine. Instead of replacing the damn things i was thinking of just having them removed to gain a bit performance.
I know i wont pass smog without going to a "special" smog shop but how loud will the exhaust be if i just leave the resonator on but remove the cats?
I know i wont pass smog without going to a "special" smog shop but how loud will the exhaust be if i just leave the resonator on but remove the cats?
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From: Western Canada
2013 C63 AMG P31, 2014 GMC Sierra (6.2)
People here have done it. Just leave on your resonator. Are you certain its your secondary cats and not something else (IE primary cats) thats making the noise??
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300E a couple 1994 w124wagon E320 Wagon/,1971MGB Track/Rally, MG Midget Autocross ,2000 E320 wagon.
If not in CA.
racepages.com oe cats about 50 bucks.
Is your 02 under 80,000 miles if so just go to the dealer the failed one will be replaced for free.Any o2 sensor problems lately?
ohlord
you also need to make sure the debris from the cat did not foul the resonator or muffler.
Is your 02 under 80,000 miles if so just go to the dealer the failed one will be replaced for free.Any o2 sensor problems lately?
ohlord
you also need to make sure the debris from the cat did not foul the resonator or muffler.
Last edited by ohlord; Jun 17, 2008 at 11:32 PM.
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From: South Jersey
2002 C32 AMG
I have removed all four. First the secondaries (no difference felt) then the primaries (pretty sure there was no difference there, either). I thought I would gain some noticeable HP like on all other cars in which I removed the cats...All I noticed was excessive noise that sounded like a leaking set of long tube headers.
If it was one of your secondaries that went bad, cut them out and don't look back; no annoying noise or CEL. If it was one of the front cats, I would have them replaced.
If it was one of your secondaries that went bad, cut them out and don't look back; no annoying noise or CEL. If it was one of the front cats, I would have them replaced.
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From: San Francisco, CA
W203 C32 AMG, W124 E300D
I had the dealer look at it, they said it was the driver side primary cat that blew. Im over the 80K mileage warranty so ill have to either remove or replace them.
I think ill replace the primary, remove the secondary and the resonator for a better exhaust note. But will i still need a "special" smog to pass?
I think ill replace the primary, remove the secondary and the resonator for a better exhaust note. But will i still need a "special" smog to pass?
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From: San Diego
2002 C32 Black/Charcoal
I have driven a pullied, chipped, and lightened C32 with no resonator and no secondary cats (not mine, of course, as that would be illegal in CA
)
My impression was entirely positive. The car felt very fast, and sounded really mean. At highway speeds, it maybe resonated a little into the cabin, but hardly noticeable. Under hard acceleration, the car sounds very unique and nasty.
)My impression was entirely positive. The car felt very fast, and sounded really mean. At highway speeds, it maybe resonated a little into the cabin, but hardly noticeable. Under hard acceleration, the car sounds very unique and nasty.
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From: San Diego
2002 C32 Black/Charcoal
Some people have stated that they did not feel a difference after removing the secondaries.
My $.02: The C32 engineers designed the C32 motor to run with *** PSI of exhaust backpressure. They designed the cats, the resonator, and the muffler to maintain this amount of backpressure. On a stock C32, removing any of the exhaust components will probably have either no effect or a negative effect on engine power, as the backpressure will fall below what the C32 motor was designed for.
However, it seems to me a matter of logic that, if you have increased air/fuel consumption by increasing boost (i.e., pulley mod), you will also increase exhaust backpressure. In that case, the removal of some of the exhaust components, and consequent reduction in exhaust backpressure, will bring the C32 back to its optimal backpressure figure, and the result will be full enjoyment of the increased air/fuel consumption resulting from the pulley mod.
I think this makes sense?
My $.02: The C32 engineers designed the C32 motor to run with *** PSI of exhaust backpressure. They designed the cats, the resonator, and the muffler to maintain this amount of backpressure. On a stock C32, removing any of the exhaust components will probably have either no effect or a negative effect on engine power, as the backpressure will fall below what the C32 motor was designed for.
However, it seems to me a matter of logic that, if you have increased air/fuel consumption by increasing boost (i.e., pulley mod), you will also increase exhaust backpressure. In that case, the removal of some of the exhaust components, and consequent reduction in exhaust backpressure, will bring the C32 back to its optimal backpressure figure, and the result will be full enjoyment of the increased air/fuel consumption resulting from the pulley mod.
I think this makes sense?
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From: San Diego
2002 C32 Black/Charcoal
Is the part number for the primaries the same as the part number for the primaries? If so, maybe you could contact one of the members who has removed his secondaries and buy one from him.
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From: Seattle
w203 m112
-j0hn
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From: San Francisco, CA
W203 C32 AMG, W124 E300D
Ok coming back to this thread, i removed all 4 cats and the resonator. It sounds like crap in the front. Rear muffler sounds great!
So im thinking of just putting some high-flow cats from magnaflow as the primary and no secondary cats. Will i have any issues with the o2 sensors and high flow cats? I alrealy have a check engine light with the cats removed and the o2 sensors still in place.
Or should it be ok?
So im thinking of just putting some high-flow cats from magnaflow as the primary and no secondary cats. Will i have any issues with the o2 sensors and high flow cats? I alrealy have a check engine light with the cats removed and the o2 sensors still in place.
Or should it be ok?
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From: South Jersey
2002 C32 AMG
Ok coming back to this thread, i removed all 4 cats and the resonator. It sounds like crap in the front. Rear muffler sounds great!
So im thinking of just putting some high-flow cats from magnaflow as the primary and no secondary cats. Will i have any issues with the o2 sensors and high flow cats? I alrealy have a check engine light with the cats removed and the o2 sensors still in place.
Or should it be ok?
So im thinking of just putting some high-flow cats from magnaflow as the primary and no secondary cats. Will i have any issues with the o2 sensors and high flow cats? I alrealy have a check engine light with the cats removed and the o2 sensors still in place.
Or should it be ok?
Anyway, I tried replacing them with metal substrate cats but they did not last long. The metal substrate quickly failed (I believe due to extreme heat). The C32 is specifically designed to transfer as much heat to the cats as possible for quicker cat light off. That's why the front cats are mounted so close to the engine (Mercedes also used double walled manifolds and a single exhaust valve rather than two exhaust valves). I don't believe the metal substrate cats can handle this level of heat, as it is merely corrugated foil. I have purchased Magnaflow ceramic cats instead; I think they should be able to handle the heat.
If you still get a CEL after replacing with high flow cats... feast your eyes
:http://www.msprotege.com/forum/showt...hp?t=123634664
http://forum.e46fanatics.com/showthr...ht=o2+defouler
http://www.inlinefour.com/blcelelad.html
http://weapon-r.com/english/index.ph...oducts_id=6219
http://www.statracing.com/buy/blox-ce.asp
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W210 E55 & W204 C63
Could you guys post a vid or two of no res + no cats. or no cats. I have res deleted and I've been worried about losing performance if I delete the secondary cats, but after reading this thread and some peer pressure I'm considering doing it.
Vids plz.
Vids plz.
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Joined: Apr 2008
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From: San Francisco, CA
W203 C32 AMG, W124 E300D
My car has about 113K miles on it.
The dealer and many exhaust shops are charging $1500 per side for replacement cats. If your going to replace the cats you have the buy the entire pipe with the 2 cats on each pipe. At $1500 retail my guess is wholesales is about $750, it isnt worth it to me to replace those cats if im going for performance mods.
Ill try the ceramic cats as advised.
The dealer and many exhaust shops are charging $1500 per side for replacement cats. If your going to replace the cats you have the buy the entire pipe with the 2 cats on each pipe. At $1500 retail my guess is wholesales is about $750, it isnt worth it to me to replace those cats if im going for performance mods.
Ill try the ceramic cats as advised.
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From: sf
Merc power
I have driven a pullied, chipped, and lightened C32 with no resonator and no secondary cats (not mine, of course, as that would be illegal in CA)
My impression was entirely positive. The car felt very fast, and sounded really mean. At highway speeds, it maybe resonated a little into the cabin, but hardly noticeable. Under hard acceleration, the car sounds very unique and nasty.
)My impression was entirely positive. The car felt very fast, and sounded really mean. At highway speeds, it maybe resonated a little into the cabin, but hardly noticeable. Under hard acceleration, the car sounds very unique and nasty.
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W210 E55 & W204 C63
This is without res cats on right? http://youtube.com/watch?v=qtHq3kSFpfY
