egt probe install but what does these temp mean?!!!

hey,
i just got my egt probe installed and finished wiring up the gaugue itself, i am at idle-gauge reads 300-400degree, at ~4K rpm and the egt gauge shows me 1000degrees!! sometimes when i accelerate it will show me 1100 degrees!!

what does this all mean? the more rpm the more the heat the gauge will show. so, how do i konw that i am running lean/rich?

i am really confuse ont he usefullness of this gauge.

 

If you want to know if you're running lean or rich, get a wideband O2 sensor. Egt gauge is only gonna give you a read out of your combustion temp and kinda just gives you an idea of how hot your engine is running. If its running too hot, then time to check the engine/ignition timing and fuel system out. As long as you're below 1400-1500 degrees, it should be ok for an FI car.