[Honda100]

As people have said, since it's FI, you are going to have a Throttle position sensor. So at a certain opening, you're going to have the computer thinking a certain amount of air is going in (it doesn't know that your TB is smaller) so it'll be calculating for the larger TB bore. That, and while i am not sure if the Jeep uses a MAF or a MAP, either one's readings are going to be off of what's actually going on. I'd say, just don't do it.

Also, I had a Mitsu Lancer a while ago which used the variable intake runner "thingy" which broke. It got stuck on "low speed" setting, and the mpg only went up maybe by a half an mpg, and it's questionable if it was down to the intake or not.