Greg - since allowed modifications cannot perform disallowed functions, I don't buy those hypothetical work-arounds.[/b]
It's not an illegal function. Even ex-Rules Nerd Greg doesn't see a problem with this, and I'm not being facetious (really!). Remember, we're talking about a hypothetical situation here where the current ECU housing rule doesn't exist. Thus,

- I can put in, for example, a TPS position sensor and gauge in my car, correct? Gauges are free; show me where it says I cannot do put in a TPS gauge. And,
- Since ECUs are free and there's no longer any housing situation problem, and one of my inputs to the computer is TPS, I can tap into the wiring of that allowed TPS gauge to wire that input to my ECU. Same goes for MAP sensor (MAP pressure gauge) and whatever else I can dream up.

The only thing keeping me/you/him from doing that now is the housing rule. Short of not installing one of the case screws (hardware is free, and we all agree air is a material) there's no way to get that wire into the ECU without modifying the factory wiring harness and plug.

It's really that simple. There's really not much that I can think of that you can't almost do now...and if you're clever (see removed screw above) you probably can.