Q: Runs rough after it gets warm

Hello, It sounds like you may possibly have a stuck EGR valve. The EGR valve allows the flow of exhaust gases into the intake manifold in controlled amounts. When you start the motor, the valve remains in a closed position, blocking the flow of exhaust gases. Once the engine reaches operating temperature and speed increases, the valve, either through vacuum or electronic control will gradually open, allowing burned exhaust gases to enter and combine with the air-fuel mixture inside the combustion chamber. When the EGR valve is clogged or dirty, as they are prone to, it may not function properly causing the engine to idle rough, stall at idle speeds, cause the car to get poor fuel mileage, or emit a strong smell of fuel due to excess hydrocarbons which also results in failing emissions tests. I would suggest having an expert from YourMechanic come to your location to diagnose and inspect your vehicle.