I've always wondered, instead of trying to fool the ECU, why not just make it learn by reprogramming it. I can understand you'd rather fool it so you don't VOID your vehicles warranty, but what about the older vehicles that no longer have their factory warranty's? You can get a chipped ECU or have your existing ECU chipped, and get something like Hondata, Neptune, or eCtune so you can change how you want your vehicle to run and let the ECU do the thinking, opposed to messing with knobs. With the knobs on the EFIE/MAP, some set their fuel mixture too lean, and then they don't have power when they need it, or they're just not running efficiently enough.
Anyway....just thought I'd bring this topic up since I haven't seen anyone bring this idea into the mix.