Need the rest of the code. It probably starts with a P so that is fine, but I need to know if the codes are P0303 & P0305 or P1303 & P1305. If the codes are P0303 & P0305 then they stand for cylinder mis-fire (cylinders 3 & 5). If they are P1303 & P1305 then they stand for Exhaust Gas Recirculation Calibration Fault & Exhaust Gas Recirculation Calibration Low.