i have a b16a with a p72 ecu in a ek hatch and starting up the car it idles at around 2k then drops to 1.5 and stays then when i drive it sometimes start to go up and down from 1-2k rpms how can i fix this idle issue,

 

I would firstly look for a vacuum leak. Check all the hoses connected to the inlet manifold; they should be all intact.

Has there been any work done to the engine, recently?

 

i took it to get inspected and was told there was no leaks or anything like that they told me to try replacing the iacv but aren’t 100% sure if that would even fix it and i’ve had this idle issue since i bought the engine when i unplug the iacv the idle drops but i was seeing its possible that its not even the iacv

 

The IACV (Idle Air Control Valve) is normaly closed. If you take it off the car (two 8 mm bolts, you need 12mm socket, and two ccolant hoses) the white thingy inside should be all the way to the left. If it is stuck to the right, i.e. there is passage open from lft to the right opening, you will have high idle. So, that is visual confirmation if the IACV is OK or not. From expirience, when IACV goes bad, engine normally would not idle on its own. When engine reaches working temperature, unplugging IACV should let idle drop to 600 rpm, or even the engine should die. If that does not happen, it means you have some excessive air entering the engine.
Possible spots: vacuum hoses (fuel pressure regulator, brake servo, Purge cut solenoid, Positive crnakshaft ventiation valve), injector seals, inlet manifold seals to head, throttle body.
Lets assume your vacuum is ok. Have you replaced injectors or someone before? If injectors are not seated properly into rubber seals, you will have leak and high idle.
Finally, has anyone been messing with idle adjusting bolt on throttle body? It might be open too much and letting excessive air into engine. Also, throttle butterfly, has it been tempered with? If it is not closing all the way, again excessive air is entering the engine and you have high idle.

 

be sure all grounds are clean, and properly attached.