I have just replaced 6 injector for brand new, because they were leaking - as you said. But problem still didn't resolve.

I discovered another thing. If I press quickly throttle pedal to the metal, engine is starting to choking between 1-2k rpm. But if I hold rpms at high level ( more that 4k) for few second and then I press throttle quickly engine works great so maybe there is some problem with catalysts or exhaust system at all?