I have acess to a CO2 machine and setup my car to around 3.5 running 10 psi about 2 months ago, all was fine boosting ok etc, then it started to miss on boost! so i checked it again and was leaned right out to 0.6!! anyway i reset it to 4.5 and turned boost to around 15 psi, again it was pulling hard and running superbly untill yesterday it has started to miss on idle slightly and quite bad on boost, im gonna get it back on the machine and set it up again.

what i would like to know is this just the car being a MFI or do i have a problem thats throwing the mixture out? i.e metering head etc?

thanks in advance