METHOD AND SYSTEM FOR CYLINDER IMBALANCE DETECTION

Methods and systems are provided for detection of cylinder-to-cylinder air fuel ratio imbalance in engine cylinders. In one example, a method may include indicating air fuel ratio imbalance in an engine cylinder based on a comparison of an estimated cylinder acceleration for the cylinder and a calibrated cylinder acceleration for each of the engine cylinders. The indication of imbalance may be further confirmed based on one or more of an exhaust air-fuel ratio, an exhaust manifold pressure, and an individual cylinder torque weighted by respective confidence factors.