Nissan Repair: Stalling at Idle, air control valve, idle air control valve

Question
2000 Sentra SE 2.0 5-speed.  55,000 miles.  My check engine light was recently on.  The code suggested replacing the front O2 sensor (bank 1?).  After doing so, the light turned off and the car ran well for a few days.  Now, when I am driving, if I shift the car into neutral, or depress the clutch, when the engine speed should drop down to idle, the needle drops to about 500rpm, then either bounces back up to the regular idle, or stalls out.  It will also stall out occasionally when moderately decelerating while in gear.

I have also noticed that at idle, the lights dim, then brighten when the engine is revved.

The check engine light is not on.  Please help!

Answer
Gianni,

The idle air control valve needs to be cleaned or replaced.  Your idle is too low because the throttle body is dirty along with the idle air control valve.  Also, if you have not done a tuneup this would be the time to replace the plugs as a minimum.