surging Milano

["Colin Verrilli" <verrilli@domain.elided>]

I'm having a persistant surging problem with my Milano (75 V6 2.5). When
(and only when) the O2 sensor is connected, I get surging on acceleration
and sometimes crusing. I can rule out many things since I just did an engine
rebuild which included: valves, rings, O2 sensor, cat converter, injectors
cleaned. I checked for proper operation of the O2 sensor with a Volt
meter. I visually checked for vacuum leaks...couldn't find any. When the
O2 sensor is disconnected, it runs fine (but a little lean, so I don't want
to run it this way with a new cat).
Any advice?
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Colin Verrilli           <verrilli@domain.elided>        IBM Raleigh, NC

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