My Ranger has failed TX. emissions with high HC and NOX readings. on 1993 Ford Ranger

Has new plugs, wires, coils, ICM, ECM, harmonic balancer pulley, new T-belt and crank sensor. Repaired/replaced vacuum lines. Smells a little rich at idle, at times, MPG is solid @ 24 mpg, mostly hiway 12 mile range to work.
need help pretty bad.

Asked by for the 1993 Ford Ranger