Dedicated exhaust gas recirculation control systems and methods

An engine control system of a vehicle, comprising:

• a fuel control module that controls fuel injection of a first cylinder of an engine based on a first target air/fuel ratio that is fuel lean relative to a stoichiometric air/fuel ratio and that controls fuel injection of a second cylinder of the engine based on a second target air/fuel ratio that is fuel rich relative to stoichiometry,
• wherein the first cylinder outputs exhaust to a first three way catalyst (TWC), and
• wherein the second cylinder outputs exhaust to an exhaust gas recirculation (EGR) valve;
• and
• an EGR control module that controls opening of the EGR valve to:
• (i) a second TWC that reacts with nitrogen oxides (NOx) in the exhaust and outputs ammonia to a selective catalytic reduction (SCR) catalyst;
• (ii) a conduit that recirculates exhaust back to an intake system of the engine;
• and
• (iii) the first TWC.

An engine control method for a vehicle, comprising:

• controlling fuel injection of a first cylinder of an engine based on a first target air/fuel ratio that is fuel lean relative to a stoichiometric air/fuel ratio,
• wherein the first cylinder outputs exhaust to a first three way catalyst (TWC);
• controlling fuel injection of a second cylinder of the engine based on a second target air/fuel ratio that is fuel rich relative to stoichiometry,
• wherein the second cylinder outputs exhaust to an exhaust gas recirculation (EGR) valve;
• and
• controlling opening of the EGR valve to:
• (i) a second TWC that reacts with nitrogen oxides (NOx) in the exhaust and outputs ammonia to a selective catalytic reduction (SCR) catalyst;
• and
• (ii) a conduit that recirculates exhaust back to an intake system of the engine;
• and
• (iii) the first TWC.