P1339 and p0420 error codes, oil loss, knocking

I own a 2015 model 1.2 e-VTI gasoline automatic car. The car has 160,000 miles on it. * There is significant oil loss in the car. The dipstick is dry at 1000-1500 km. There's no real cost. I constantly add oil. I use Total Quartz Ineo HTC 5W-30 oil. Regarding the oil loss, Eurorepar service said that an engine overhaul is required. Other mechanics said there's no need to open the engine right away and to check the surrounding elements. The technician at the Bosch service suggested I try an engine repairer. I used Rislone engine repair oil additive, but the oil loss continues. It didn't help at all. * P1339 - combustion disorder (catalyst effect) 3 N cylinder injector * P0420 - loss of catalyst efficiency. There are fault codes. * The authorized service said that the catalytic converter might have reached the end of its life due to the oil loss and should be replaced. I had it cleaned, and almost no dirt was removed. The guy who did the repair said the sensors might be faulty.* The car makes a knocking noise when starting off, especially in 2nd gear, and goes away when accelerating. It vibrates a lot at idle, but there's no fluctuation. Other than that, the car drives very well on the flat. It can stall a lot on steep inclines. On long roads, it can stall a little on inclines, can't accelerate, or can gradually lose speed. I don't know much about cars or engines. What should I do in this situation? What should I look for, what should I focus on, should an engine overhaul be done? rasmus2023-07-17 15:13:37

Hello, Master, first of all, I wish you a speedy recovery. My humble advice is that replacing the piston rings seems to solve this problem. I don't think a direct overhaul is necessary. Once the engine is half-opened, the mechanic will look at the liners and make his decision accordingly.

Is there any service recommendation in Izmir regarding this issue?