Abstract: An oxidation catalytic converter system for small spark ignited engines includes a housing containing a catalyst, an inlet for receiving exhaust gases from the engine, and an outlet for discharge of the exhaust gases from the housing after passing through the catalyst. Attached to the engine exhaust is a jet pipe that extends into the inlet in noncontacting relation to the housing, whereby the catalytic converter is vibrationally isolated from the jet pipe. Surrounding the jet pipe is an annular air gap through which ambient air is drawn into the housing and mixed with the exhaust gases for enhanced cooling and catalyst performance.

Abstract: Apparatus is provided for mixing an oxygen containing gas, for example air, with exhaust gas from a liquefied petroleum gas (LPG) fuelled internal combustion engine, the mixture bieng supplied to a catalytic converter to reduce the level of carbon monoxide in the exhaust gas. The apparatus comprises a first duct for supplying the exhaust gas to a catalytic converter, and a second duct having a closed end extending transversely into the first duct for supplying air to mix with the exhaust gas. Opening means are provided in the wall of the second duct to allow air, pumped under pressure to the second duct by an engine driven pump, to flow into and mix with the exhaust gas.