[texanidiot25]

I've heard of some people running piggy-back'd ECUs with a stand-alone unit (for lack of a better description). Main reason is so that the OBDII computer is still there for when it comes time for emissions testing. Otherwise, the aftermarket unit carries the engine's duties for horse power.

I would figure you could setup the aftermarket unit to run lean, and just have it wired to a switch I suppose. Easier than having to manually adjust the a/f ratio or monitor the mpguino. You could map an entire lean burn mode for the whole RPM range and have all the backup systems needed to protect the motor.