It is a Forrester SH ecomatics, i.e. with factory LPG with 120tkm. Error picture: After a cold start the engine does not take a gas for a short time (I did not measure it, it felt about 30 seconds). The engine starts easily and absolutely inconspicuously immediately and then runs stable with its elevated stationary gas. As soon as I give gas the speed drops until shortly before dying down and stays down until I go again from accelerator, then it “shoots” once briefly, sinks but then immediately to the increased idle speed. This he does always, always only for a certain time and afterwards runs again inconspicuously. It also does not matter whether a gear is inserted or not. There is no MIL, no error and in error memory is also nothing deposited. I noticed this problem for about 6 months and I have the feeling that it gets worse. At this point I would actually exclude the gas system as a cause of error, first of all the at this time Inactive, second, I have no other problems and thirdly, I made the last trips to work on gasoline to exclude them and the behavior was exactly the same. Does anyone have an idea? FreeSSM is available, should I read certain values with it?