Try warm starting with the gas pedal held open. If it's flooding due to leaky injectors, this should help it start easier. If it's no difference, or harder to start that way, then it's likely not flooded. The miss at idle could be gas fouling, which may account for the O2 light. Another common problem for a miss at idle is oil getting past the valve seals and guides. Mine does this a bit, and it's getting new seals as soon as the heat and work give me a break. Keep an eye on oil consumption. For this, and other issues, you'll find the Search function to be very useful.

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1989 300 SEL that mostly works, but needs TLC