So I have 2001 Honda Accord 2.3l 4cylinder it had a f23a4 with is the ulev vtec and I was burning oil so I swapped it with a F23A1 and when I finished swaping it I forgot to put coolant in and took It for a drive i heated up and i stopped and put coolant and then I got a check engine for a knock sensor so I changed that and cleared the code with a ob2 scanner and now when ever the ob2 scanner isn’t in it struggles to start and sometimes wants to turn off while driving

 

This is a ground issue.
With the scanner plugged int it provides a ground path through the scanner for the PCM. IIRC there are two grounds on the OBDII port one is a chassis ground the other is the PCM ground, which the scanner combines and completes the ground circuit for your. I *think* the grounds are pin # 4 and #5(VERIFY!!!), so if you run a jumper to those two it may temporarily solve the issue until you can fix it correctly. There is a reason why the grounds are normally divorced.
Recheck your engine harness main body ground, ground bonding jumpers and main battery grounds to the engine and the body.

 

Thank you I had a ground cable lose