Sulfur-resistant SPGM catalysts with significant oxidation capabilities are disclosed. Catalytic layers of SPGM samples may be prepared using incipient wetness and metallizing techniques to structure a washcoat layer of ZPGM material of YMnO3 perovskite , and an overcoat layer including Pt/Pd composition on alumina-silica support oxide. Loading of PGM in OC layer is less than 5 g/ft3. A testing methodology for samples may be enabled including of DOC light-off, and soaking under isothermal DOC and sulfated DOC conditions to assess synergistic influence of adding ZPGM to PGM catalyst samples. Resistance to sulfur and catalytic stability may be observed under 5.2 gS/L condition to assess significant improvements in NO oxidation, HC conversion, and CO selectivity. Resistance to sulfur of disclosed SPGM catalyst may be compared with performance of an equivalent PGM control catalyst for DOC applications.