96 ls rpm fluctuation with steady throttle
 

As the title describes the car is a 92 eg w a b18b1 completely swapped from a 96 ls integra. Recently at a constant throttle (me holding the pedal steady) the rpm's are fluctuating about 1k in either direction. When accelerating i notice a hesitation at times. Other times i notice a substantial power loss, hesitation, and then normal operation. When i unplug the tps and allow the car to run in the default map or "limp mode" the problem is gone. I changed the tps to no avail. I swapped the ecu with another p75 and once again with a p28 w hondata s300 loaded with the stock b18b1 settings. Problem remained with both ecu's. Full tune up done recently on the engine (plugs, wires, cap, rotor, timing belt). I checked the fast idle valve and cleaned it. I even swapped with a known good part. I Datalogged with hondata and all the parameters for the sensors read good as far as i could tell. I suspect possibly the o2 sensor since it is shown in voltage on the log rather than a/f ratio. I will research the conversion from voltage to actual ratio and see if that is an issue. Also i have had a mechanic tell me possibly the crank sensor could cause this conditon. ANY INPUT IS GREATLY APPRECIATED. I dont really want to throw parts at it so any info regarding testing is also appreciated.