IA95civicDX

My car back fires/ gets stuck at aroun 3500 rpm... its not my dailey driver and it sat all winter, in which i robbed a 02 sensor and the spark plugs from it, for a car a just sold. I put a another o2 sensor on it as well as spark plugs and now it runs like ****...?? btw motor is a jdm d15b and i put a 4 wire o2 sensor on and im runing a p.08 with the motor, and its thowing a cel.

ANY HELP WOULD BE GREAT
thanks