1998 Isuzu Trooper eratic idle

Engine Performance problem
1998 Isuzu Trooper 6 cyl Four Wheel Drive Automatic

1998 Isuzu Trooper: Check light came on, codes read both o2 Sensors I changed them light is still on. My symptoms are when cold all is well after a ride, turn off and when started again while hot, idle is erratic, up down sometimes stalls. When I put in drive forward, or backward it idles normally and acts just fine? The symptom will not return until I turn off the ignition and then soon after while still hot start the car again. If I let the car cool down let’s say in 1 hour it will start and run perfectly, it also runs perfectly until I begin the turn off ignition and while hot start the process again. I did some research on IAC valve, this seems to be my best bet, please give me your thoughts. I can’t find any vacuum leaks.
Regards, Richard