Could be the O2 sensor, it should read about 0.45 volts on idle. If its giving no signal back it will add more fuel.
If you have a aftermarket FPR, uprated fuel pump or different injectors, they can all cause the rich idle as well.
Change the o2 sensor this morning..still 11.5 on idle..any other tips guys
What voltage are you getting back from the O2 sensor now?