Acceleration stumble

[Dave Head <dhead@sundial.sundial.net>]

89 tq - new plugs, chipped. Has 85% 1050 rpm idle (16-17" vacuum), 15%
850-900 rpm idle (14" vacuum). When warming up idle will swing a bit (say 1
second intervals) between the two. I would say this occurs when the ECU
switches to closed loop.

With gear shifting acceleration (moderate or hard), will stumble/miss for a
few seconds then clear its throat. Clears quicker if I back off a bit. Not
pinging. 93 octane - various sources.
I'm leaning toward O2 sensor bad. Other ideas possible: fuel filter,
injectors, plugs, cap/rotor. 

Any BTDTs?
********************************AUDI FAN*********************************
                EMCM(SW) - retirement 30 Apr... Dave Head  
87 5KCStq 249K miles - fer sale, durned good price
89 200q 181K miles - awaiting cleanup
    qcusa #3442                                           Oviedo, Florida     
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