High-Flow Catalytic Converter for BMW E46

[Cadeez]

Every once in a while I have a little rattle at idle coming from the cat under the car, probably time for a new one. However from doing a little research it looks as if we have 3 cats on our cars...is that right? One off each cylinder bank from the manifold, cylinders 1-3 & 4-6, and then is there a third one under the passenger area? I found replacements for the manifold ones on Turner's site for $400 ea, yikes, but not for the third cat. Any recommendations on a nice high flow cat that isn't $1k bucks?

[mikeyb74]

Are you sure it's a cat and not just a heat shield? The thing that is under the passenger seat is just a resonator. I too have a rattle at idle from time to time which is a loose heat shield.

http://www.realoem.com/bmw/diagrams/c/y/121.png

[Cadeez]

That's what I thought it was originally so I got underneath the car on a lift and pounded on the entire exhaust to recreate the rattle and got nothing at all. So the only other thing would be a rattling cat when sometimes the insides are jarred loose. But as I said it's intermittent, so who knows. But no matter how nice your car looks, if it's sitting there rattling...that's ghetto.

[ZSP-Mafia]

There's a thread over on bfc about using magnaflow cat's here in CA. I don't recall if they're available for the e46, but they are only $200 or so each.

[Johnmadd]

Did you beat on it with a rubber mallet or your hands?

[Cadeez]

With my hands, but I was really banging on it...

[danewilson77]

In for update regarding CAT replacement, and in for hearing from Cadeez. I need me some Cadeez.