The official notice
Defect
CERTAIN MEDIUM DUTY C-SERIES AND B7 SCHOOL BUS CHASSIS EQUIPPED WITH A 7.4 LITER GAS ENGINE AND AN IMPCO LPG CONVERSION KIT. SOME OF THESE VEHICLES MAY HAVE ENGINE BACKFIRES WITH SUFFICIENT FORCE TO DAMAGE THE ENGINE AIR INTAKE SYSTEM AND THE AIR CLEANER FILTER ELEMENT.
Safety Risk
IF THE DAMAGED AIR CLEANER PARTS ARE DISLODGED FROM THEIR NORMAL POSITION, THESE PARTS COULD COME IN CONTACT WITH THE HOT EXHAUST MANIFOLD AND/OR HOT EXHAUST GAS RECIRCULATION (EGR) VALVE TUBE RESULTING IN A POSSIBLE ENGINE COMPARTMENT FIRE.
Remedy
DEALERS WILL INSTALL A REDESIGNED MIXER BONNET AND AIR CLEANER HOUSING COVER, SELECTIVE UPGRADES IN VARIOUS CONNECTIONS RELATED TO THE AIR INDUCTION SYSTEM, AND IF NEEDED, A NEW AIR CLEANER FILTER. OWNER NOTIFICATION BEGAN DECEMBER 18, 2002. OWNERS WHO TAKE THEIR VEHICLES TO AN AUTHORIZED DEALER ON AN AGREED UPON SERVICE DATE AND DO NOT RECEIVE THE FREE REMEDY WITHIN A REASONABLE TIME SHOULD CONTACT CHEVROLET AT 1-800-222-1020 OR GMC AT 1-800-462-8782.