I bought a 2000 beetle with what seems to he a awp motor (317cc injectors, ko3s turbo & vvt). The car still has the original APH ECU. Every now and then the car will stumble on deceleration under load ( ac on and turning the steering wheel). I verified all timing Mark's, no vacuums leaks and no ECU codes. Would the APH ecu have trouble keeping up with the larger injectors and require me to get a tune? Any advise would be greatly appreciated.