When I first got my '93 3 years ago, I found a stutter/hesitation at between 45 and 50 on a light/steady throttle. Anything other than that and it was unnoticeable.
It went into Lexus Canterbury and spent 2 hours on their machines, they put a new Lambda sensor in and it made a marginal difference that lasted about a month.
I've now got used to it, its no better and no worse, I've changed all the usual stuff, Plugs filters, leads etc etc and nothing makes any difference - I just live with it. (Like I live with the blown clock and the A/C screen and the fact that I have no dashboard lighting until the temp gets above 7 degrees, and no tacho needle ever!)
Its probably one of the computers, but finding which one plus buying another would probably cost more than the cars worth so............
Dave