Cataclean Fuel & Exhaust System Cleaner

Cataclean uses a concentrated aromatic solvent blend — xylene at 30–50% with acetone and IPA co-solvents, not the PEA-class detergent chemistry typical in this category. In the fuel zone it dissolves varnish and injector deposits via direct solvent contact. The catalytic converter claim operates through the combustion pathway: the formula combusts in the cylinder and byproducts interact with the converter substrate. The brand states this reduces hydrocarbon emissions; independent corroboration is absent, and community results are mixed. Pour one bottle into a low-fuel tank quarterly or before an emissions test.

Best for owners with borderline catalytic converter performance, mild O2 sensor codes, or upcoming emissions tests. Works across gasoline, diesel, hybrid, and flex-fuel vehicles. Skip it for a physically damaged converter — solvent treatment cannot restore a failed substrate. Skip it if you consistently use Top Tier gasoline. For misfires, rough idle, or injector failure beyond typical fouling, professional service is the right call.

SDS §2 classification is DANGER (H304 aspiration Cat 1), with H315 (skin irritation), H319 (eye irritation), and H336 (narcotic vapor effects). Do not induce vomiting if ingested — seek medical attention. The Prop 65 warning covers ethylbenzene and naphthalene. The product combusts in the engine — exhaust byproducts are the environmental endpoint; the 825 g/L VOC and category ceiling cap environment at 3/10.