1995 Nissan 200sx Check Engine Light On Code Reader That Speed Sensor Replace

my check engine light is on, the code reader says that speed sensor.. so i replace it with a new one, when i start it , the engine runs rough and the idle is playing.. is the speed sensor cause this? does it to be align? i put back the screw back in and i dont see anything that i have to align it.. but before that i replace the speedsensor the car wont start , the battery is good is just no spark! i do some research that it might be the spark plug/wires, so i replace them out too! but then after that the car runs rough.. pls help!