P0302 cylinder two misfire

Today that hose has been fixed, and this time i've been to another serviceman. I'm adding the image of the old hose, its awkward its fixed in 3 places. So back to the problem, while the other guy said both of the O2 sensors are allright, this serviceman noticed the first O2 sensor might be faulty, because its value is oscillating around 0.43V and 0.48V meanwhile the second has the good values, moving between 0.1V and 0.9V. I've seen on internet, when the mixture is good, its on 0.45V, and going up/down correcting the mixture. I would ask it, is it really faulty? While he tested it, he got the System too lean (Bank 1) fault code aswell. Can this be the cause of the relatively high idle consumption aswell?

The second one was moving ok. The first one has only low amount moves between 0.43 and 0.48, even when we raised the rpm to 3-4k. So you are saying that the first o2 sensor with this move is ok, its not faulty?

I've found no one who can perform a smoke test. I don't know, this country is fucked (Hungary), atleast the car mechanic part of it.

That hose (which I added the image about) was changed with a new one, but i've seen something interesting yesterday, the short and long fuel trims (Image attached). By the way i've already ordered the Bank1 O2 sensor, I got it for only 28 dollars, for a try to fix the problem its not a big investment (compared to injectors and EGR valve). Its possible I have a bad O2 sensor, AND still atleast one more vacuum leak? Also i've seen on the internet, an absolutely dirty air filter also can cause the rough idle stuff, tomorrow i'm going to check it aswell (as far as I know it hadnt been checked when we bought the car, half year ago).

The first picture is the cable of the current bank1 o2 sensor, the second the pipe from the plastic label, air filter. I hear a hissing sound, probably from that pipe, that can effect the air-fuel ratio? I will try taping it, to see if it makes the temporary fix.

I've seen on the internet I can do a smoke test with cigar/vape. I'd ask it, which hose should I blow into? Also I installed the other O2 sensor (on the picture the left one is the old one), I got good values with it in voltage, also the short and long term fuel trims are good, but the exhaust is still sputtering, and the idle is relatively rough, but feels a bit better now. Does it have an adaption time? I've heard something like that it has to adapt to the new sensor.

We've been looking for vacuum leaks with Carb cleaner (with engine on), and there is no more leak, even the tube which i've posted a picture about, is not leaking. With the O2 sensor, I got better short and long term fuel trims, but now I got a double code for misfire, and the engine is constantly misfireing, I can hear the sputter on the exhaust. Im absolutely lost right now, what the hack it could be.

We already tried that, few weeks ago. Only ignition coils swap, but misfire remained in cylinder 2.

I can feel it only at idle, it got no loss of power while driving.

I dont know the exact numbers of the pressures on the cylinders, but I know it was tested, I think in january, and the serviceman said its good on each cylinder.