Life does suck with rough idle/missing

[IronBMW]

Anyone tried to replace his Catalitic Convertor? temperatures should be low pre-cat, high after cat, but mine is the opposite, I think this is indication about a blocked cat which making this idle missing.

[IronBMW]

well, above message was about the 98 bmw, mine is 99.
I just brought it back from the auto electrician, as a result, no luck at all.
He replaced Cam shaft sensor, Oxygen Sensor.
He did smoke test, there was no leaking. He checked it by scope, he said it was so clear, means all good. according to him Cat. is alright. He gave up. He said it is possible carbon in Intake manifold or the head itself, I used Seafoam to clean the head from carbon, and took it on Motorway for a good drive, but still same.
He suggested it is possibly Injectors problem, I added injectors cleaner in fuel tank, but i need to see how it will go with that one, I am not so optimistic about this one.

[IronBMW]

I cleaned MAF today with MAF cleaner, test it, still same, no change at all, still that missing there.

I talked to some guy he said this type of cars has a design error, not enough air going inside the engine. In USA they started to install Turbo to solve this problem.

I found leakage in DISA valve, seal it with sillicon, no more leaks, but still no difference in performance or vacuum measurment.