I think we can say for sure the lambda is buggered.
Where did they come from?

I don't know manufacturer, but one finnish company imports these, I don't think that this was even good quality part.

I did have problems before with crap lambda, That is why I used an old 400 one.

Well, got on offer from exhaust manifold and lambda sensor in it, maybe soon I will get much nicer graphs.

Coolant leak could destroy lambda, but I have not seen any coolant level dropping. Also some gaskets could make lambda broke, but I think that I don't have any gasket material that would go to exhaust pipe.

Must check how long next lambda will last, if there is still problems, then I can't understand this anymore

Thanks from tips.