Patent ID: 6938410

Claim:
A system comprising: a variable displacement internal combustion engine, the engine arranged in a V-configuration; a first emission control device coupled to a first group of cylinders of said engine; a second emission control device coupled to a second group of cylinders of said engine; an intake manifold coupled to the engine; an electronically controlled throttle coupled in said intake manifold; a manifold pressure sensor coupled in said intake manifold downstream of said electronically controlled throttle; a first exhaust gas oxygen sensor coupled upstream of said first emission control device; a second exhaust gas oxygen sensor coupled downstream of said first emission control device; a third heated exhaust gas oxygen sensor coupled upstream of said second emission control device; a fourth exhaust gas oxygen sensor coupled downstream of said second emission control device; and a controller for determining temperature of at least one of the emission control devices; controlling activation of at least one cylinder based on said determined temperature; and operating already operating cylinders at an air-fuel ratio based on information from one of said exhaust gas oxygen sensors.