Honeycomb ceramic substrateHoneycomb substrateceramic substrateAutomobile exhaust gases are conventionally purified with a catalyst supported on a ceramic body able to withstand high temperatures. The preferred catalyst support structure is a honeycomb configuration which includes a multiplicity of unobstructed parallel channels sized to permit gas flow and bounded by thin ceramic walls. The walls of these channels provide the surface for precious-metal catalysts that convert noxious emissions into carbon dioxide, nitrogen and water vapor. We can provide honeycomb ceramic substrate has been coated and non-coated precious-metal.