Hi!
Right coilpack went bad and I ordered new one from ebay. Before was entire bank out, now cylinders 1-3. When I clear codes and start driving, for moment it has all power and then faults come back. Replaced sparkplugs, voltage transformer, injectors seemed in good condition, compression is decent, swapped o2 sensors, but nothing. Is that new(remanufactured) chinese coil bad?

I think you found your problem

knock off brand wires are ok to use usually but the coils not so much

s600 does not use spark plug wires