This Preliminary Information communication provides information to the technician that engineering is asking for additional information if SI diagnosis leads to replacement of the Indirect Fuel Injector for a P0420 Diagnostic Trouble Code. Technician should follow published Service Information diagnostics for Diagnostic Trouble Code P0420. Technician will need to also gather quantity of fuel flow measured, engine hours, type of vehicle, and estimated percentage of time the vehicle spends at idle.
