Zeolite-based honeycomb bodies and methods of manufacturing same. Zeolite-based honeycomb bodies especially suited for engine exhaust treatment applications include a primary phase comprising a zeolite having a SiO2 to Al2O3 molar ratio in the range from 5 to 300. The zeolite-based composites are porous with an open porosity of at least 25% and a median pore diameter of at least 1 micron. The zeolite-based honeycomb bodies can be manufactured by an extrusion method.