The computer is probably fine, but it gets information about how well your vehicle is running from the O2 sensor(s). That would be the first thing I would check based on your description of the problem. If you have a bad sensor, the computer won't be getting information about the fuel/air mixture, and won't be able to adjust the engine accordingly. Some vehicles have just one, while others have multiple sensors. The O2 sensors will wear out over time, so if you haven't had yours checked or replaced in the last couple of years, now would be a good time to do it.
A mechanic will be able to attach a diagnostic tool to your computer and tell you if the O2 sensor is bad, among other things. Make sure you take it to a reputable mechanic, though.
I have the 97 grand cherokee with 4.0. I have been having problems with intermittent stalling and backfiring. I tried the backing the screws out from the computer. it helped but here's what I have noticed as of recent. When I take the battery cable off for a few seconds to work on something the next day the jeep runs like gold for the first day but then as the computer is resetting itself that is by the second or third day the intermittent stalling continues. Does this mean I need a new computer for it? Or could I get a mechanic to rest the parameters on the computer? Please help!