Did I miss the part where you did compression and leakdown tests?

If so, what were the results?

Also, using eehack or the shop's scanner, what are the injector open times on each bank?

I have never seen a car with rich exhaust smell, lean O2 reading and sooty plugs require MORE fuel.

If it's actually lean enough to cause a lean misfire, there will be even more unburnt oxygen in...

It's mechanical....ish.

You're running so rich that you're not getting a complete burn.

This means that some unburnt oxygen is making it into the exhaust, which reads as lean. Start leaning it...