Rick,
Poor acceleration on low ocatane fuel means that for some reason your computer is retarding your timing (which means it thinks you are getting knocking or detonation), the computers don't really retard large amounts of timing smoothly, sorta "bucks and sways" a little when it does, it feels like a sudden decrease in power output. Just leave the hall sensor for now, it's something that's best messed with when you have REAL time to fiddle and pull things apart (it's mounted in the base of the distributor from memory... The early turbos don't have a REAL problem with those...) The o2 sensor cannot be cleaned at all. I've heard people recommend to change them every 80,000k's or so, i don't believe that....if you KNOW the sensor is newish, then leave it, if not, change it, because if you have to have a SMOG test, it won't pass without a proper functioning one. I was wondering if you know how to use a digital multimeter, or have access to one? I know how to test the knock sensor, and that is to put the multimeter onto "megaohms" range and testing the reading from the knock sensor, from memory it should be around 1.5 Mega ohms......or there abouts, no reading = DEAD anything below 1 Mega Ohm indicates its got a problem.... Then, once you measured that (if you got 1.5 Mega ohms or so, if not, go get one from a wreckers, if it IS the problem, you want to change it NOW as you have a turbo, they are rather important), change the multimeter to "volts" range, 2 volts or 20v range or something low like that, and grab a hammer (yes, a hammer) and *tap* not *HIT* but tap on the bolt holding in the knock sensor, you should see a significant jump in the voltage reading as you hit it. Significant means about 1.5 volts....
Hope this helps a little,
Az