M5 Expert (>4000)
Join Date: Feb 2001
Location: west palm beach. fl.
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Originally Posted by louiscipher1965
I have had problems passing emissions when I got the car, changed the MAFS, and the CATS, and now I get one code stating that the cat on bank 1 is bad.
What is really weird is that the light at times go off and comes back on later right now it is on, and the car drives fine.
I don't think that is the DME problem the software update is designed to correct. You are getting a fault code. Check carefully for exhaust leaks. If original cat, there should be a weld; if replaced, often you see a simple clamp where the new connection was made. You say you replaced the cats, so double check those connections.
Cats do go bad, but not often, and they don't heal themselves, so intermittant light says probably not the cat.
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