Nissan Repair: 1993 Maxima, haynes manual, octane boost

Question
I have 1993 maxima that runs ruff at idle and driving when cold has new plugs wires and one new fuel injector added injector cleaner and octane boost this has helped

Answer
Bill,

Check the EGR valve for proper operation.  Next check the throttle body to make sure it is clean.  If both of these are good then the throttle position switch probably needs to be replaced.  Get a Haynes Manual for the values and a cheapie volt/ohm meter to check the sensor.  With the years it is probably past due.