2008 1.6 VTI Automatic Steep hill starting problem

Hello. My car is a 2008 model 1.6 VTI automatic. It has 171,000 km on it. There is no LPG. The car does not start on steep hills. Even when I floor the gas, the revs do not exceed 1300-1400. I just had the catalytic converter drained. According to the exhaust technician, a EURO3 catalyst was installed beforehand. I have had the car for 4 years. I did not have it installed. These cars have an AL4 fully automatic torque converter transmission. About 10,000 km ago, the oil pressure sensor and 2 solenoid valves were replaced. I was receiving transmission errors caused by the sensor. With the replacement of the valves, the knocking when shifting into 2nd and 4th gears stopped. The spark plugs were also changed 37,000 km ago. There is no misfiring in the car. I wrote all of this in case it helps you with the problem. What could be the problem of the car not starting on hills, or what do you recommend I do? Thank you everyone in advance.

This is off topic, but I wonder how much it costs to replace and maintain the solenoid for the AL4?

Since your vehicle probably has a problem with its transmission, have your vehicle checked for errors again at a specialized service center that has original software.