This Preliminary Information communication provides information to the technician about vehicles that have a Service Engine Soon Malfunction Indicator Lamp on, engine misfire, and/or engine noise. Technician may find Diagnostic Trouble Codes P0300-P0308. If published Service Information diagnostics does not isolate the cause of this concern technician should check for a worn camshaft lobe and/or lifter roller, a sticking valve, valve leakage, a broken valve spring, and a collapsed active fuel management lifter.
