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Headers on E39

Discussion in 'E39 (1997-2003)' started by 303358, Feb 26, 2009.

    303358 guest

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    Hello, I'm teaking an E39 and have a set of equal length headers, now where to put the cats??
    Anybody done this, ideas?

    thanks,
    michael
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    mooseheadm5

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    Year and model might be helpful

    303358 guest

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    E39 Headers

    Sorry- '02 525i with cats in headers
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    mooseheadm5

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    That may or may not cause problems with OBD2 since the cats are designed to be very close to the head for emissions reasons.

    303358 guest

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    My thoughts exactly, the 528 had the cats down stream anybody that has tried that move?
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    mooseheadm5

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    My guess is that they had to move them closer to the head for faster warmup. Moving them downstream that far is what worries me. I would bet that you get a check engine light from the cats and O2 sensors not heating up fast enough.

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