ForumZebra

hey as we know the stock cats on the c32 are restrictive, has anyone upgraded to a free-flow cat like those on ebay?such as this

http://cgi.ebay.com/ebaymotors/ws/eB...001590946&rd=1

would a high-flow cat increase HP and make the sound better? anyone upgrade their cats? thank you for your experience on this

ForumZebra

hey as we know the stock cats on the c32 are restrictive, has anyone upgraded to a free-flow cat like those on ebay?such as this

http://cgi.ebay.com/ebaymotors/ws/eB...001590946&rd=1

would a high-flow cat increase HP and make the sound better? anyone upgrade their cats? thank you for your experience on this

MarcusF

I would be very surprised if a $38 ceramic substrate cat flowed better than a functioning OEM cat. You may want to consider a metal substrate cat.

ForumZebra

1 more question does mercedes place the 1st Oxygen sensor in the header pipe before the cat and then place the 2nd Oxygen sensor in the pipe that comes right after the cat? or does mercedes place the 2 Oxygen sensors into the cat itself? becuase if i replace it i dont want to move the Oxygen sensors i just want to saw off the mercedes dual-cat and weld into its place the ebay free-flow one

rlee02135

try flowmonster...they're all over ebay for $50

MRAMG1

WRONG.

The stock cats are VERY good for flowrate. Hence the VERY minor increase in HP people have received from replacing the ENTIRE exhaust.

Oh yeah, why in the world would you believe a $40 cat from E-Bay would actualy work

That goes hand in hand with their $40 electric superchargers for sale that give you 80 HP.

Sorry ForumZebra, didn't mean to flame you, but come on. You own a Benz and are thinking these are good parts.

See yeah

MarcusF

The MB exhausts I’ve seen have the O2 sensors mounted in the pipe.

A "saw"? You may want to look at a $20 pipe cutter. A pipe cutter requires less room, takes less time, makes straighter cuts, and your arm won't feel like it's going to fall off when you're done. That, and $5 ID/ID pipe connectors make this a DIY project that only requires hand tools. Connecters have the added benefit of allowing people to swap in a straight pipe in under an hour.

Yes, I have been known to cheat a little. But only a "little".

ForumZebra

are the sensors located in the pipes BEFORE and AFTER the cat? or are they INSIDE the damn cat, look in the pic

are they where the blue arrows are or has mercedes drilled holes into the cat to plug in the oxygen sensors? because i dont want to buy a hi-flo cat and drill holes in it to place the damn oxygen sensros

crazeazn

there should be one pre cat and one post cat. thats how it mantains emissions? my is300 was that way....

ForumZebra

so the oxygen sensors are NOT in the cat, right? they are in the pipes before and after the cat? am i correct?

Sidez

also the sensors are located in only the front 2 cats.. the rear 2 cats can be removed and it wont affect the sensor whats so ever.. this is what I have done on my car, although not a c32 it is very similar... and I am happy with the difference.. it made the car sound a bit better, but there was no increase in performance whatsoever... well maybe .00000001 in the quarter due to the reduction in weight... however you will not pass emissions...

the AMG exhaust fitted on these cars is already top notch, but what does bother me is that the stock manifolds are the same as 320 and that can't be good with a boosted engine...

Sunn Ova Gunn

zdrasvutje but the ebay seller says it passes inspektion with 1 high-flow con-shaped cat. incase it doesnt pass cant the inspektor guy just put a generic car to the sniffer and pretend its my car? i mean who cares, its not like the EPA Police are driving around testing peoples fart cans for toxins

c32AMG-DTM

I guess they could, but good luck finding that - it's illegal for them to do it, so why should they? FWIW, it's also illegal to remove a cat that's functioning normally - even if you're replacing it with another.

The exhaust on the C32 is really, really good already - if you're looking to improve anything performance-wise, improve the headers. For sound improvement/increase, remove the resonator. Then, call it a day w/ exhaust mods, and turn your attention elsewhere...

Slater126

Everyone always wants somethin' for nothin', heh. Notice how custom exhausts are very seldom mentioned for the C32. German performance cars typically have outstanding exhaust systems, at least from a performance perspective. The only reason to go aftermarket is for the sound. Personally, I wouldn't let a $40 E-Bay anything touch my car, but that's just me.

Sunn Ova Gunn

i did remove the rezonator but i thought i should also remove that damn cat it blox hp as well as the benz growl. last year the mechanix i went to put their own car to smog sniffer but this year they were reluctant, i wonder what got them so skared? the only solution to this is i will go cat-less and make one of these mechanix my friends, and always go to him if thers a problem, many tips, and his favor would be passing my car for inspection every year.

its every benz owners dream to remove those restrictive cats, its like placing a rock inside the exhaust tube and telling the air, "ok now you can move freely"

JToups386

Uh, actually, the EPA does do just that. I've known people who have lost their license to do inspections as well as the shop being fined as much as $10k for doing fake inspections. 10+ years ago it was easy to do before they started sniffing everything pre-OBDII. I had many connections that would provide me a sticker for a minimal "donation" fee. Nowadays it's extremely risky, and if anyone suspects such activity, all they have to do is place a call to the EPA and they'll literally stake out a shop and/or send in a decoy.
It's sad, but true. The EPA would rather go after the lowest common denominator for emissions, than pursue the real violators, ie commercial trucks, industry, etc...
Unless you're really close to someone who can do inspections, you are very unlikely to get anyone to sell you an illegal one. The risk is too high for them.

However, keep this in mind. If it's an OBDII car, (post 1996), the car simply gets plugged into the machine and if no error codes are read, the car then goes through a simple visual inspection which I highly, highly doubt they'll crawl under a Benz to verify if it has 2 or 4 cats. The law of averages is on your side there. They'll also pressure test your gas cap. No biggie...

///AMG4EVER

Can I have a troll check please.

TemjinX2

i say at least get a magflow or stay oem.