Abstract: The current invention reveals equipment and the method to utilize it to produce coated honeycomb catalyst monoliths as for catalytic converters. This invention utilizes two chambers, the first to contact the substrate with a washcoat, the second to ensure removal of coating solution from the interior of the substrate. The first coating chamber uses a precisely controlled volumetric application from below ensuring complete internal contact with no overflow from the top of the substrate. Removal of excess washcoat is volumetric, providing a relatively high pressure differential across the substrate to effectively remove all of the excess washcoat from the substrate. The second chamber provides a higher differential pressure through a similar mechanism, preferentially with the substrate inverted. Washcoat removed from the substrate in chamber two impinges on water, and is re-introduced to chamber 1 through the seal cleaning mechanism.