[keithmac]

Have a look on the Emanage boards, you can make a simple circuit that feeds a false 02 voltage to the cars ECU on boost so the car thinks it`s at 14.7:1 where in reality you can dial any mixture in you want.

I`ve pulled the 02`s completely on my 1st Gen GTO but you can`t get away with that on later cars without a CEL.

You can buy 02 simulators that will simulate stoich signal from an o2 sensor full time, this will give you total control over the whole fuel map without trimming from the cars ecu.

As Richard says, just adding more fuel be it petrol or methanol will just make matters worse if the car is actively seeking stoich from the o2 sensor.