If it's like the problem I had, it would surge/hesitate between 2-3K RPM under light acceleration/engine load. I was told it was probably a TCC solenoid so I lived with it. I found a post on here or one of the other forums and it said to disconnect the battery(both cables) and the short them together for about 30 minutes. This resets the PCM and then after you hook up the battery again the PCM will relean your driving. It fixed my problem completely. It's an easy quick(and free) thing to try.