i just installed the apex'i turbo timer in my car but i really don't know what the numbers mean on the a/f and O2 modes. can anyone tell me how to read this? and what would be considered as too rich or too lean?

14.7:1 is stoichiometric, which is generally what everyday street cars (aka: your mom's Camry) are tuned to. For more power that number can go down as low as about 12.5:1 (richer). If the output is in millivolts then the O2 sensor with read about 500mV at 14.7:1. Rich will be above 500mV, lean will be below. Unless you have a wideband O2 sensor it will be completely inacurate outside of 14.7 in either direction, so just try to keep it around there as much as you can.

Good luck

thanks