Injector stuck open, replaced still stuck open.

[ATB]

Hello, I've been trying to figure this out for months now, but I've had zero luck and I've had the car to shops even they couldn't solve it.

Car is a 1999 Yaris manual transmission.
Combi-coupe: Yaris CP10
1,0 68hk,
1SZFE

It started before Christmas, the car would suddenly run poorly and shaking at low rpms, very strong fuel smell. It would last for a short while and it wen't away. This happened a few times before becoming a permanent problem. (It ran great and I stalled it by accident) It was always one cylinder that was soaked in petrol every time the problem occurred and it was dripping petrol out the exhaust pipe. I swapped injectors and coils around but the problem stayed on the same cylinder. I read the codes but I can't remember the codes by number but it was missfire on 2-3 cylinders and ignition circuit error. I replaced plugs and it ran good for a short while.

But as I ran out of options of what to do I sen't it to my closest shop. They replaced all 4 injectors without any improvement and now they are telling me that a new ECU is in order. Does anyone have any ideas? I wan't to try every option before spending 2000$ on a new ECU and labour on a car I paid 2000$ for