Toyota Repair: 4runner, mass air flow, aamco transmissions

Question
I am looking at a 95 4 runner 4x4. 2.4L engine 5 spd. Engine light is on. The vehicles has no power until about 3500 RPM. Then it takes off like it should be running. It does not matter what gear you are in. No power and then it takes off. Would remind someone of a "power band " on a dirt bike the way it suddenly runs at 3500.  Also has exhaust leak. Mass air flow?  

Answer
We need to start by finding out what turned the check engine light on, have the diagnostic trouble code retreived and then let me know what it is, there may be more than one, most major autoparts stores get the code for you at no charge so does aamco transmissions.