SUBARU VEHICLE SERVICE CAMPAIGN: SEE DOCUMENT SEARCH BUTTON FOR OWNER LETTER. ENGINE CONTROL MODULE REPROGRAMMING. UNDER CERTAIN HARSH DRIVING PATTERNS, SPECIFICALLY WHEN REPEATEDLY OR CONTINUOUSLY OPERATING THE ENGINE ABOVE THE RED LINE (RPM ABOVE 6,700), ABNORMAL COMBUSTION COULD OCCUR RESULTING IN SERIOUS INTERNAL ENGINE DAMAGE IN THE FORM OF BROKEN PISTON RING LANDS. (IMPREZA WRX STI MODELS) CSC LETTER WAS RECEIVED. *PE