Right i got a vw polo 1.4 16v x reg as a temp till i can afford another, has a very odd issue, when i reach 3100 3200 revs in any gear it stutters shuddering the car but goes fine after, ive changed plugs filter got some carb cleaner and cleaned the throttle body and egr valve, also as precaution added k seal service light was on so manually reset, has oil good coolant, removed the thermostat also, any ideas?