This Preliminary Information communication provides information to the technician on the step to diagnose and repair vehicles that may have engine misfire and check engine light with any or all cylinder misfires only on deceleration. Technician will need to remove the accessory belts and drive or brake stall at signature RPM. If the concern is gone inspect for debris in the belt or pulleys causing a jump and false misfires. Also lift the engine to unload the engine mounts and test again. If concern is gone then inspect for a ground out concern with the mounts causing false misfires.
