Constraint the emissions to specific technologies

[Antti-L]

I think you need to use a user constraint.  COM_BNDNET sets a bound on the total VAR_COMNET, which does not have a process index at all, and so all the PSet_PN in your screenshot are ignored. However, constraining emissions of different fuels only when used by gasoline and diesel cars would require either the emissions being accounted at the vehicle processes, or modeling separate fuel technologies for gasoline and diesel cars.