Can some one help please

I have a 1995 Civic 1.5 l SOHC VTEC. I got this car and it had a bad sputer, Dam near every thing on this car is new. new motor, plugs, wires, distrubiter cap and rotor, CV joints, drive axle,o2 sensor and much more and it still wont go away. Any clue?
And now the trany went out so i pulled the motor and put a new trany in and when i started it the ideal was jumping between 1500 and 2500 RPM's, As well as bruning oil, which it did not do befor the swap!!! I did the trobble shooting and it said it was the o2 sensor so i got a new one and still have the same problom. If any one now that would be awsome thanks

iac valve? make sure all your vacuum hoses are hooked up right. as for the sputter... was youre fuel filter changed as well?