Its a Curse of DBW in my opinion.

It happens in my STi, if your shifting gears like race car on Intelligent Mode.

Im just curious on your reasoning behind it being an emissions thing?

Unburnt fuel gets sorted by PVC System. Plumbed back into the intake track for a second shot at redemption.

This is my 1st DBW Car and its the only car that I've owned does this.

I also know its cos Im shifting like race car when it happens.

If just driven Civil, granny shifting in traffic is all good.

I also don't think its an emissions thing. On S & S# there is no hang in my car, behaves like a cable operated throttle & more sensitive pedal & more power.

Little bit better then module as on I - limited to 60% throttle at max pedal depression. IE throttle plate wont open past 60% even when given the full blow.

I also don't see how it would help upshift don't you want the rev's to drop when upshifting instead of hanging around?

Its the downshift where the effect would be sort of desirable to newer drivers.