[janea1207]

hi guys, can you tell me on bmw 430i with b46 engine is 1 or 2 katalysator? i bought downpipe and install it but some people said me that after first cat is second one and also need to remove it for stage2 tune.

[spirit3d88]

you have Cat with OPF , both are in the same, from then on you have 2 resonators or anti detonators and the rear silencer.

[acevesf]

On a related note, I have a Remus axleback exhaust on the way.. do I have them remove a resonator, both?

[CandyRedRC46]

Originally Posted by acevesf

On a related note, I have a Remus axleback exhaust on the way.. do I have them remove a resonator, both?

Why would you do that lol.

[CandyRedRC46]

Originally Posted by janea1207

hi guys, can you tell me on bmw 430i with b46 engine is 1 or 2 katalysator? i bought downpipe and install it but some people said me that after first cat is second one and also need to remove it for stage2 tune.

Post pictures of your exhaust and ill tell you.

[spirit3d88]

Originally Posted by acevesf

On a related note, I have a Remus axleback exhaust on the way.. do I have them remove a resonator, both?

you will have better sound

[acevesf]

Originally Posted by CandyRedRC46

Why would you do that lol.

Do the resonators not reduce the sound of the exhaust or is it minimal? Or why shouldn’t I do it?

[CandyRedRC46]

Originally Posted by acevesf

Do the resonators not reduce the sound of the exhaust or is it minimal? Or why shouldn’t I do it?

Resonators make it a little quieter, but generally they are there to reduce drone and unpleasant tones. Catless, plus a highend resonated catback (or highend axle back and stock resonator) is where its at.

[watermannc]

You have one catalytic in your downpipe and a secondary cat for your b46 engine. After the second cat is your resonator and then your muffler. No o2 sensor is in your secondary cat so getting rid of it will not give you a cel. However if you change the downpipe to a catless one, it will 100% give you a cel unless you use a tune to clear it