Compare catalytic converter fuel additives, direct-cleaning kits and hybrid-specific formulas. Start with the application method and vehicle compatibility, then choose a single treatment or a multi-product kit.

Fuel additives are added to the fuel tank. Kits that include foam require direct application as specified on the label. P0420 and P0430 can have several causes; diagnose the fault before treatment. A cleaner cannot repair a cracked or melted catalyst, and emissions-test results are not guaranteed.