What will a rich mixture damage?

[Penny/Brandon Wood <woody@xxxxxxxxx>]

My car was stumbling, hesitating, and blowing black soot out the =
exhaust.  I replaced the fuel pressure regulator and everything has =
cleared up. (It was sticking and letting far to much gas pass thru the =
engine.) I wonder if the over the past months of occasionally but =
extremely rich mixture I could have harmed my spark plugs, O2 sensor, or =
cat. converter.  The plugs are 9k miles old, the sensor <1k, and the cat =
is original.  How can I tell if the plugs are fouled or cat blocked up?  =
Anyone know of a way to clean them up, maybe a fuel additive?  If =
anyone's interested I could post some advice on replacing the fuel =
pressure regulator.

Brandon Wood
88 M3=20
BMW CCA 127523

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