Carbon doctor only cleans intake valves correct, my point is that in direct injection,the injector nozzles are mounted in the combustion chamber and can possibly suffer from carbon formation on the nozzles and that is why injector cleaner sorted out my issue,i shared the pic to show how bad my...
Direct injection causing carbon build up that can clog up the injector and affect spraying pattern is likely the cause,took my car for carbon cleaning at 176000KM and it was filthy.
I have no experience with that specific one,I used this liqui moly that you pour into the fuel,this worked for a short while,but the fault came back and using another bottle did not clear fault, i tried the other brands after that
I solved my issue by using injector cleaner, just get an injector cleaner with polyether amine (PEA) like Techron concetrate, Royal purple max atomizer etc,i use a bottle twice or three times a year and the problem has never returned.