Question: are there any additives for cleaning catalytic converters?
Answer: #1 – Cataclean Engine and Catalytic Converter Cleaner. ...  #2 – CRC “Guaranteed to Pass” Emissions System Formula. ...  #3 – Solder-It CAT-1. ...  #4 – Oxicat Oxygen Sensor and Catalytic Converter Cleaner. ...  #5 – Hi-Gear HG3270s. ...  #6 – Sledgehammer Run-Rite Kit. ...  #7 – Sea Foam Motor Treatment.