Honda: RPM fluctuations, throttle position sensor, intake air temperature

Question
I have a 1997 4Dr LX Hond aaccord.I was getting a check engine light.I took an emission test.
and the results say

On-Board Diagnostics Codes Read-2
P0122 - Throttle/PedalPosition Sensor/Switch A circuit ow Input
P0113 - Intake Air Temperature Circuit High Input

I took to a mechanic and he has done REPLACE SENSOR/RESET ECM/TEST/MIL LIGHT and replaced SENSOR ASSEMBLY.
After replacing it there is no check engine light on and when i drove the car it was fine.The next day when i started the car  after 4-5mins the RPM is fluctuating.A weird sound is coming as if it is fluctuating...Please suggest me..

Answer
I would check the Idle Air Control(IAC) Valve.  Is it cold where you live?  If so, then there is a higher chance that it is the IAC valve according to your timing of the problem.  Then again, there may be a problem with your Throttle Position Sensor as you've mentioned above.

Best of luck to you,
Barrett.