oofreakoo

One of my catalytic converters are rattling from the inside. I have an Fab-Design cat back system on it and would like to increase the sound depth with some high flow cats. I dont want to bypass them or anything like that but since I have to replace them anyway, I thought something like the Magnaflows might work good.

Anybody using high flow cats?

Am I risking 02 sensor fault codes with aftermarket cats?

I heard a rumor that Calif law has dealers warranty cats for 4yrs or 50k miles, is this true?

TIA fellas......
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joeybenz106

what ever you buy Just make sure its a 200 cell cat.

Ballinger

I don't know about warranties, etc, but I can tell you two things about the high-flow cat I put on my 4.0 liter Jeep (as part of a 2.25" Borla header/Flowmaster system): it radically reduced backpressure and it notably increased the exhaust noise. The increased exhaust noise is a bummer, frankly...

Oh, it's neat when you first hear it, and it impresses people to hear the throaty rumble, but it's louder on the highway, louder in the neighborhood during quiet times and really telegraphs what I'm doing with the throttle on the freeway ramp, etc... I wanted the truck to have more ooomph, but didn't need the extra hotrod sound. Think about that if you're going to uncork your Benz, too.

lkchris

Don't get excited about "high flow." It's just hype to impress hot rodders.

It may be better than what comes on Jeeps, but it's not better than what comes on Mercedes.

All cats on all vehicles sold anywhere in the USA are warranted for 8 years/80K miles.

svt ricco

can you explain why? i'm planning to get one too. thanks

GotDaBenz

Hey, Joey. You have the saying reversed. It's "Better to be judged by 12 than carried by 6".

speedybenz

The 200 cell race cats I have seen have all been very expensive. Magnaflow or Catco makes some pretty nice Cats with a metal substrate and fairly nice tapered pipe sections leading to the cat honeycomb section.

Most stock cats, MB included dont have any taper going from the pipe to the cat and so the exhaust gas hits this increased area and slows down and becomes turbulent. With a nice 7-10 degree taper on both sides of the honeycomb cat section the exhaust flow will stay laminar and will more somoothly enter the cats and exit better, which will result in an increased flow. also the metal substrate cats have a thinner x-section and this also helps to reduce backpressure vs. a longer ceramic cat honeycomb section.

If someone has a source for resonalbe priced 200 cell cats, please share.

Jeff

amgalex

Make sure your replacement cats are metal and not ceramic substrate as ceramic does not last as long, does not withstand higher temperatures as good especially on a big Mercedes motor. And unless they are 200 cell they are not really high flow cats.