
Now all injectors are good as new. I got those cleaned because the car started to lack power and made a strange clicking noise when driven.. Hopefully no burnt valves or anything because of the lean mixture, though I didn't drive it much after the symptoms started.

It cost 30 euros per injector, all renewable parts were changed, injector was cleaned in a ultrasound machine and after that cleaning liquid was run through the opposite direction of the fuel flow to get all debris out. Spray pattern was also tested before and after the cleaning and some leak-tests were also performed.

It's not too expensive, one new injector would've cost ~100 euros.
http://koti.mbnet.fi/mtn/images/autot/GLT/suuttimet.JPG
I should've taken "before" pic too. I didn't even know before that those were metallic colored.
