MotorPower Care Catalytic converter cleaner is the best cleaning solution kit, dissolves soot & carbon, and is High quality made in Germany:

Intensive cleaning for the catalytic converter, this kit includes two products, one for the tank and the other foam we spray directly on the catalyst from the Oxygen sensor (O2) sensor port. This kit will fix the catalytic converter’s failure if the catalyst is not cracked, broken, or melted. This kit saves more than %70 catalytic converters when they fail to pass smog or check engine light with a catalyst or O2 sensor codes, this kit gives incentive cleaning for the catalytic converter, and it’s safe on the materials inside the catalytic converter; it’s a very high-quality new technology design by the leaders in this industry. ADVANTAGES – Removes existing deposits – Protects against heavy dirt with regular use – Provides the engine performance Restores – Ensuring the proper operation of the oxygen sensor/catalyst / the turbocharger and the EGR valve – Prevents or eliminates problems that appear on OBD Product properties: For use in all petrol and diesel engines and hybrid vehicles.