Recent studies suggest that microwave energy can be employed in catalysis and that the results differ from "conventional" heating. The influence of microwave energy on automotive exhaust catalysis in the presence and absence of a catalyst poison (SO2) was studied. The conclusion is that microwave energy can induce carbon monoxide (CO) lightoff (the temperature where 50% of final conversion is achieved) more efficiently than conventional heating and can reverse the poisoning by SO2 for a commercial three-way catalyst.