Patent attributes
An exhaust gas purification system for an internal combustion engine includes a particulate filter (also referred to as GPF) to collect particulate matter (PM) in exhaust gas, an automatic transmission including a torque converter with a lock-up clutch, and a controller that controls the internal combustion engine to perform fuel cut when the internal combustion engine is decelerating and a temperature correlation value of lubricating oil (ATF) is higher than a determination value, and controls the automatic transmission to engage the lock-up clutch during execution of the fuel cut. The controller is configured to estimate a deposit amount of PM deposited on the GPF, and change the determination value to a smaller value than before the deposit amount exceeds a first deposit amount when the deposit amount exceeds a predetermined first deposit amount.