At 2000 rpm in all gears my jeep will miss, like when taking off or trying to cruise at 60 mph under light throttle it is quite noticeable. Is there any gasket that could be affecting this or a vacuum leak? I have replaced a lot of parts and had it scoped 2 times and scanned but no culprit?? It is a 90 auto with a 4.0. exhaust/intake gasket was done too. The thing that seemed to help the most was a cap and rotor, think im looking in the wrong direction with a gasket or vac leak?