Alright so im pretty sure this problem has arrisen plenty of times on this forums but i was looking for a little input

I bought my friends accord off of him cheap because he needed money for school, thee were some slight problems and one of them happens to be the bouncing idle. I notice it doesnt do it all the time just about 95%. There is no check engine light but i already went ahead and cleaned out the Iacv as well as I could, checked all vacuum lines put new clamps and even replaced a few hoses. I have read that it could be air in the coolant but i highly doubt that just because its consistent. It has an intake on it and now i noticed when i was cleaning the iacv and took off the intake that the piping leading from the throttle body to the filter had a hole in it that was letting unfiltered air into the throttle body. My friend said this has happened before and he just replaced the throttle body/intake manifold and that worked for a year or so and it just started doing it again. Would this be the cause of my problem?? And if so what could i do to solve this?? (Also why on earth would he knowingly let unfiltered air into the throttle body is beyond me?) I have also read on this forum someone did something with there MAP sensor and it fixed the problem (theyre situation seemed similar to mine) Any input is greatly appreciated! thanks

edit: I Also have noticed that if im cruisin on the freeway in 5th and exit when i throw it into neutral and stop it wont do it and will idle around 1000-1100 but never higher. This problem occurs whether the car is hot or cold

 

Check that PCV valve is working (loose and checks flow in one direction). Stuck-Open PCV could cause bouncing idle.

Check bleeder on top of intake manifold for air by cracking when engine is cold to confirm not trapped air.

good luck