Confirm the catalytic converter is actually clogged
Check for exhaust leaks, bad oxygen sensors, misfires, or fuel system issues first
Read diagnostic trouble codes with an OBD-II scanner
Inspect the air filter, spark plugs, ignition coils, and fuel injectors
Repair any engine problems causing excess fuel or oil to enter the exhaust
Use a catalytic converter cleaner additive if the clog is mild
Drive the vehicle at highway speed after using the cleaner to help burn off deposits
Remove and inspect the catalytic converter if symptoms remain
Replace the catalytic converter if it is melted, broken, or severely restricted
Replace damaged oxygen sensors if needed
Prevent future clogging by keeping the engine tuned and fixing check-engine issues promptly