2006 Mitsubishi Lancer Evolution Engine 'hicup'

Good Day Gents,

Evo IX from 2006 with numerous aftermarket parts, having the latest ones being a Magnus v5 cast intake manifold in conjuction with an AEM EMS stand alone system with appropiate tune done on street as well as dyno tuned. Car is equipped with a wideband o2 sensor.

Issue happens in any gear (though rarely, maybe once or twice in a 20 mile drive) and independent of rpm or AFR reading. It seems to hold itself for a second, maybe less and then continue as if nothing has happenned. New spark plugs were part of the job too. Best way to describe is as if it just has a hicup, or a pause in raise of rpm band. New walbro 255 fuel pump was part of the deal too as well as 880cc PTE injectors.

Car has exhaust manifold, all piping replaced, as well as intake/exhaust cams, though only part left to swap is the turbo; still stock turbo. Maybe because of the big plenum mani its just choking itself briefly because in need of air?

Is it programming. Hardware or software? No sounds from engine, and clutch and flywheel are brand new too, plus the hicup wasnt happenning before the new stand alone with intake mani.

Thanks,

JC

No sounds are made, just that quick 'jerk' of the car.