My Theory
Step 1 Replace fuel injectors with 30%? larger.
Step 2 Let ECU adapt to these injectors
Step 3 Modify 02 sensor in a way that the ECU thinks the car is running lean. Volatage conversion in line between 02 and ECU
If the ECU sees a lean condition from the 02 it will adjust again and run what it thinks is the appropriate amount of fuel.
If anyone can figure out how to make this work let me know........