i have had one injector changed i know its not plugs or wires misses on one cylinder
how to replace fuel injector on 1993 Nissan Altima
You can check prices here for that injector http://repairpal.com/estimator?car_type_id=1043 and locate a shop here http://repairpal.com/directory?address=42330&car_brand_names=Nissan
before you do this, the intake gasket is a common failure for a miss. get a smoke test at a shop to confirm.