1999 Honda CRV Surging idle

Hi so I’ve tried everything short of replacing a whole bunch of parts for no obvious reason. I think that I’ve narrowed my problem down to the IACV or the ECU. My idle only starts surging after my car has been running for a couple of minutes from a cold state. If I cover the top hole in my TB with my finger the car shuts off so I’m pretty sure I don’t have a vacuum leak anywhere, with that said I have gone through and checked for vacuum leaks and I have found none. I already tested the TPS and the MAP sensor they are both working as they should. I removed and cleaned my iacv, and even bought a replacement(not OEM). Still surging, I noticed however that if I remove the air filter box and hose that connects to the TB there’s a noticeable increase in suction when the surging starts as if the iac suddenly opens up. That’s what I’m having trouble figuring out. if I disconnect the IACV the surging is very subtle but the idle stays in between 1100 – 1500 rpm. I need all the help I can get, I’ve already tried watching a ton of videos and reading a bunch of articles nothing has helped.