What are the causes of catalytic converter damage and single/multiple cylinder misfires?

[LaSawyer]

Catalytic converter damage and single/multiple cylinder misfires can be caused by the following factors: 1. Catalytic converter damage: Loss of surface precious metal activity; Blockage due to carbon deposits from ethanol gasoline usage, sulfur-phosphorus chemical compound sintering, lead-manganese metal deposit sintering, or ceramic substrate melting caused by engine exhaust flames; Prolonged exposure to high temperatures. 2. Single cylinder misfire: Ignition system failure; Engine malfunction issues, etc. 3. Multiple cylinder misfires: (1) Poor spark plug contact: Momentary ignition failure causing cylinder cut-off. (2) Excessive injector self-induced voltage: Resulting in sticking during the next operating cycle. (3) Poor heat dissipation: Inadequate transistor cooling in ECU causing ignition coil failure. (4) Insufficient cylinder pressure: Leading to ignition failure.