Patent ID: 7464543

Claim:
A silencer/catalytic converter unit for a combustion engine, the silencer/catalytic converter comprising: an oxidation catalyst configured to reduce emissions in an untreated engine exhaust; a first volume connected closest to the combustion engine via an inlet, and configured to dampen spurious exhaust pressure excursions and remove at least a portion of the particulates contained in the untreated engine exhaust; a second volume housing the oxidation catalyst; and a pressure relief valve disposed upstream of the second volume, in communication with the first volume, and configured to relieve said first volume to outside the silencer/catalytic converter unit at a pressure greater than the maximum normal operating pressure of the combustion engine exhaust to avoid excessive pressure excursions of the combustion engine exhaust from damaging the oxidation catalyst; wherein the first volume and the second volume are in communication with each other; and wherein the first volume is upstream of the second volume and the oxidation catalyst.