Exhaust treatment apparatus and method

An exhaust treatment apparatus for an internal combustion engine, the apparatus comprising:

• a manifold chamber defined by an exhaust manifold and containing a catalyst;
• a plurality of exhaust gas inlets for supplying exhaust gases from the internal combustion engine to the manifold chamber;
• an exhaust gas outlet for supplying exhaust gases from the manifold chamber to a turbocharger, wherein the catalyst has a three-dimensional open structure for facilitating a flow of exhaust gases from the exhaust gas inlets to the exhaust gas outlet;
• an injection nozzle for introducing a reductant into the exhaust gases between the catalyst and the turbocharger, wherein the catalyst is carried on a substrate, the substrate defining the three-dimensional open structure and filling the manifold chamber;
• a first recess formed in the catalyst coincident with each exhaust gas inlet;
• and
• a second recess formed in the substrate coincident with the injection nozzle.