Abstract: A procedure is introduced to diagnose a catalytic converter system with at least two catalytic converters, through which separate exhaust gas flows flow, with the steps: test if oxygen storage capacities of the catalytic converters, which are at least two in number, exceed a predetermined threshold value. The procedure characterizes itself, in that the oxygen storage capacity of the first of two catalytic converters is compared with at least one first threshold value, in that an additional threshold value is ascertained as a function of a result of the comparison and in that the oxygen storage capacity of the second of two catalytic converters is compared with the additional threshold value. Additionally a control device is introduced, which executes the procedure.

Abstract: A procedure is introduced to diagnose a catalytic converter system with at least two catalytic converters, through which separate exhaust gas flows flow, with the steps: test if oxygen storage capacities of the catalytic converters, which are at least two in number, exceed a predetermined threshold value. The procedure characterizes itself, in that the oxygen storage capacity of the first of two catalytic converters is compared with at least one first threshold value, in that an additional threshold value is ascertained as a function of a result of the comparison and in that the oxygen storage capacity of the second of two catalytic converters is compared with the additional threshold value. Additionally a control device is introduced, which executes the procedure.

Abstract: A process for coating three-dimensional, electrically conductive substrates by applying a coating layer of a stoving coating composition substantially only to the exterior surfaces of the substrates at a layer thickness sufficient to electrically insulate such surfaces, stoving the coating layer and then coating the interior surfaces with an electrodeposition coating composition, wherein the stoving coating composition is characterised by a volume resistivity from 108 to 1011 Ohm·cm of applied and stoved coating layers of said composition.

Abstract: Aqueous coating compositions suitable for multi-layer lacquer coatings which contain binders based on water-dilutable polyol compounds in the form of hydroxy-functional poly(meth)acrylates, polyurethanes, polyethers, polyesters and/or polyester-modified poly(meth)acrylates together with crosslinking agents based on aminoplastic resins, phenolic resins, free and/or capped polyisocyanates prepared using poly(C.sub.2 -C.sub.3)alkylene glycol di(C.sub.1 -C.sub.4)alkyl ethers.

Abstract: A process is described for producing multilayer coatings in which a first coating layer of a first aqueous coating medium is applied to an electrically conducting substrate by electrophoretic deposition, is provided wet-in-wet with a second coating layer of a second aqueous coating medium, followed by joint stoving, wherein a coating medium based on one or more vehicles stabilised by ionic groups and which crosslink on stoving with the formation of urethane groups is used for the second coating layer, and the coating media are selected so that the maximum pigment/vehicle weight ratio of the first coating medium is 1:1, that the ratio of the pigment/vehicle weight ratio of the first coating medium to that of the second coating medium is up to 1.