CeO is used as an oxidation catalyst in catalytic converters. It is formed by catalytic oxidation of ammonia. Exhaust manifolds are of tubular construction with integrated catalytic converters. It involves a regenerative change in the oxidation state of the catalytic metal. Some palladium is emitted with the exhaust gases of cars with catalytic converters. Leaded gasoline contaminates the oxygen sensors and catalytic converters. This is the reverse of the catalytic hydrogenation of alkenes. Vehicles without functioning catalytic converters generally fail emission inspections. Filters require more maintenance than catalytic converters. Power was reduced to for versions having catalytic exhaust system. The L56 is emissions controlled with EGR and catalytic converters. Residues involved in catalytic activity are bolded. Cl and Br atoms destroy ozone molecules through a variety of catalytic cycles. Acyl ligands are intermediates in many carbonylation reactions, which are important in some catalytic reactions. Some models were also equipped without catalytic converters.