Gas pipe element sensor let pass other gases than selected

This kind of automation works fine as long as the pipe you are putting the excess of the shutoff isn't full or blocked. That can be accomplished by giving a different rout to the third element you are putting in the pipe (carbon dioxide) or put bridges to set priority to the pipes you want (the excess of the shutoff).  What is happening in your build is that carbon dioxide from the generator stalls the excess of the shutoff (input you don't want) so the sensor detects the next packet while the previous one is still on top of the shutoff and can't go anywhere. Shutoff opens and unwanted packet of gas ends up in the output of the shutoff instead of going through the other pipe.

The pipe marked with arrow will have priority over the outputs bridges will bring (I connected the pipes just so gases can go round and round)

Awesome, I understand whats happened now, and I will work around it! 

Thank you mate!

Changed Status to Closed