Ford/ Mazda 4x4 Auto has developed a skip/ buck at low RPMs while in high gear. on 1999 Ford Ranger

Have replace plugs wire twice, EGR Valve, intake gasget twice, and fuel sensor.

1 answer 1 comment
is the check engine light on?
No not at this time... Just had a vacume leak test with smoke and checked plugs, wires again still skips when warmed up but not when cold. It is like a miss or buck in high gear 1500-2000 RPM.