An exhaust poison trap for protection of catalytic converters in automotive exhaust systems includes a tubular housing having open ends and a peripheral wall internally defining an exhaust chamber, a helical wall longitudinally dividing the exhaust chamber into at least two longitudinally extending helical passages for exhaust gas flow and porous means substantially covering the interior of the peripheral wall and forming an outer periphery of each of said helical passages, whereby exhaust gas passing through the exhaust chamber is directed in a helical path through the helical passages, causing particulate matter in the gas to be accelerated outwardly by centrifugal force and trapped in the porous means, thus protecting a downstream catalytic converter from trapped catalyst poisoning particles such as zinc and phosphorous. The porous means may be coated to improve trapping or to aid catalytic reactions in the exhaust gases.
展开▼