I have 2002 accord running an f20b engine never came with distributor I put an obd1 internal coil distributor on it but I知 hearing I should run an obd2 distributor but if I知 doing an obd2 down step to obd1 would this cause any problems?

 

You would need to wire the TDC, CKP and CYP sensors accordingly. 2002 Accord would have had 2 of the 3 sensors located down behind the crank pulley / mounted to the oil pump housing. While the OBD1 engine would have all 3 sensors located in the distributor.

Also have to watch that the distributor that you are using isn't out by 180* once it is mounted on the engine. I know this was an issue for some F22 engines, I'm not 100% on the differences between the F23a and F20B obd1 and obd2 distributors though.