2001 Integra LS

Motor was recently rebuilt and had a major tune-up. All belts and gaskets, plugs and cables were replaced.

Everything seems to be good except the at idle the needle is jumping up and down, sometimes to as low as 500rpm. Also noticed that whenever the radiator fans come up, the interior lights kinda flicker (this might be a different problem)

Cleaned the Idle control valve
Valve adjustment

Yesterday it threw a P0172 running rich code and I reset it with a scanner and it haven't come back yet.

What else could it be?
-Map sensor? but shouldn't it throw a code if it has a problem?
-Timing Cam is off?
-Vacuum leak?

Compression is good though.