There are 2 catalytic converters in OEM downpipe?

SupraCal

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Hi gents,
I was analyzing our OEM downpipe and noticed there is a 5 inch catalytic converter after each O2 sensor insertions. - circled in pic.

Does that mean if I were to remove the 1 after the 2nd catalytic converter, and reuse the downpipe, theoretically the CEL should not come on?

I am looking to increase the sound of my exhaust, but the catless downpipe CEL is really getting into me. (I would like to tune it out only later as warranty is important to me for now, and catted aftermarket downpipe is not a consideration for now )

would be most obliged if any technical wiz/ tuners can chime in on this. would be great if I can have the gases flow faster and give some sound and not get CEL!

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Reppunkamui

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Yes, it should be fine in theory. Aftermarket catted downpipes (like AA), do not have the second cat and does not trigger CEL.

If exhaust sound is your main aim, I would first look at setting the exhaust flap open all the time. Then changing the exhaust tip, before removing the cat honeycomb. But it is your car, so your call...
 

AlRayes_BRN

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Yes, it should be fine in theory. Aftermarket catted downpipes (like AA), do not have the second cat and does not trigger CEL.

If exhaust sound is your main aim, I would first look at setting the exhaust flap open all the time. Then changing the exhaust tip, before removing the cat honeycomb. But it is your car, so your call...
Some people did get CEL with AA dp, the one that I know of that doesn't give you any CEL issue is AFE catted downpipe but it's 400 CPSI compared to the 300 from AA + the smaller diameter.

The OEM downpipe looks like 600 or 700 CPSI.
 

Reppunkamui

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Some people did get CEL with AA dp, the one that I know of that doesn't give you any CEL issue is AFE catted downpipe but it's 400 CPSI compared to the 300 from AA + the smaller diameter.

The OEM downpipe looks like 600 or 700 CPSI.
To my knowledge, AA guarantees no CEL. I have no idea who got a CEL running it, did they check the error code to make sure it was the cat?

Either way, this is a irrelevant/distraction to OP's question. I.e. one cat is sufficient and that the second cat should not be relevant for CEL as there isn't an O2 sensor after it.
 
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Extreme Power House

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To my knowledge, AA guarantees no CEL. I have no idea who got a CEL running it, did they check the error code to make sure it was the cat?

Either way, this is a irrelevant/distraction to OP's question. I.e. one cat is sufficient and that the second cat should not be relevant for CEL as there isn't an O2 sensor after it.
Active Autowerke guarantees no CEL, out of thousands of these downpipes sold, I'm aware of a couple of customers that got the CEL. As far as I know, Active Autowerke took care of it and replaced the downpipe free of cost.
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