The rough running at above idle speeds may well be associated with the injector ground points as Aaron indicated. It would sure be simple if those connections are the problem. In case not, I'll prattle on with some of my own thoughts as I may not get a chance to follow up on this thread for a while.

Some other things I'm aware of with rough running are fouled spark plugs, loose spark plugs (B234F prone), engine deposits (cheap fuel), unmetered intake air leak, slightly flaky AMM, cam seal oil leak into distributor, weak distributor coil (original B234F style) and weak rpm sensor (original B234F style).

As for the 2-3-2 code (O2 sensor), for the benefit of other readers you got that off the #2 (fuel) diagnostic and properly reset the code afterward. My manual is just as cryptic as yours on this code, but I think you'd find it means the O2 sensor signal is not within a defined range given the other operating signals present at the ECU, ie. a sick engine. This might well just be a red herring associated with engine conditions at stalling (that's when I used to see this code). It may also be an indicator that the car needs some really good runs to burn off deposits (esp. using a top quality injector cleaner gas additive).

As for stalling at idle, here are some of the more common things you should be aware of with the LH 2.4 system used on the B234F:

-The IAC (idle air control valve aka. idle air motor) must not have a sticky motor. This can result from a dirty valve or a worn internal commutator. The valve should move and spring back to normal when you twist it in your hand. If you know how, the diagnostic socket can be used to fully exercise this valve which can help to loosen any dirt
-The throttle body must be clean. That means the throat area, the vacuum line fittings (ream the small one with fine wire) and the throttle plate (esp. around the edge).
-The throttle plate must not be binding in the throat. If you hold the throttle up to daylight with the plate fully close you should see an even amount of light around the plate.
-The TPS (throttle position switch) must be clean and properly adjusted. Just setting it to for a "click-click is a bit crude. This should be done using the diagnostic socket and a feeler gauge.
-The throttle linkage should be properly adjusted to spec, especially the throttle stop screw.
-There must be no unmetered air leaks into the intake system, especially split or disconnected vacuum hoses, a split air intake tube, or a loose throttle body.
-The flame trap and PCV system should be clean for proper engine breathing and to prevent oil spitting into the throttle body.
-The operating signal from the AC to the ECU should be checked. This is done using the diagnostic socket. The only problem likely here is a bad wire.

Any of these can cause or at least aggravate idle stalling problems, especially when the car is cold and put into gear or when the AC is turned on. Beyond that there is no adjustment for idle, it's all done by the ECU. LH 2.4 ECU failures almost always result in a no start situation rather than poor running.

I earned my B234F merit badge wrestling with chronic stalling problems with my own car.

-Dave '89 740 B234F