Patent ID: 8413497

Claim:
An abnormality diagnostic device of an internal combustion engine with a turbocharger having a turbocharger, which is used for supercharging an intake air by driving a compressor with the use of an exhaust turbine provided in an exhaust passage of the internal combustion engine, a wastegate valve, which is used for opening and closing an exhaust bypass passage bypassing the exhaust turbine, and a catalyst for purifying exhaust gas, the abnormality diagnostic device comprising: abnormality diagnosing means for performing inter-cylinder imbalance abnormality diagnosis for determining existence or nonexistence of an imbalance abnormality among cylinders of the internal combustion engine based on an output of an air-fuel ratio sensor provided downstream of the exhaust turbine and upstream of the catalyst in the exhaust passage, wherein the abnormality diagnosing means performs the inter-cylinder imbalance abnormality diagnosis when the wastegate valve is open.