Gas but no power.

[S13n310]

Hey guys,

Quick question I hope some of you can help me with. When driving on low gears 1-2 my car accelerates fine but when i punch it say on an on-ramp it will rev, my engine light will turn on and while some power will reach the wheels, it starts to sputter and i have to let off the gas. Any ideas??? thanx... Oh I have an 89 240sx, automatic transmission, stock engine.