I really want to run the ethanol sensor and have the PCM control fueling based on composition.

I see posts here and there about people running hacked tunes to get this done and I am specifically referring to using a COS (I am boosted). OS for the 2002 Tahoe L59.

Only other options are to repin to an 03+ pcm

or

HPtuners.

And I don't want to do either of those.