Need Input for Solving Issues

[Casey10s]

On the last couple of track days, I have had some issues and would like to get some input on possible causes/solutions.

I changed my rotors and pads before my last track day. Everything seemed normal until the end of the second session. Under medium to heavy braking, I started to hear some noises that sounding like something wasn't smooth (not necessarily grinding but maybe something was dragging) but no real vibration. The few times I have had the car out on the streets since then, I noticed it was probably coming from the front driver's side. Any ideas? I was thinking either wheel bearing (which should be noisy all the time), caliper going bad, or maybe something else. Any suggestions? I also took the pads out and checked them out also looked at the wheel and rotors. All wheels/rotors look OK.

Also I started to use an OBD reader. I was getting funny lights coming on the dashboard as I started to connect my phone to the OBD unit. Things like lost communication with different control units was the code reason. This happened like 3 times over 2 track days. Can the OBD reader cause that? Anything to worry about? It seems to go away if I turn the car off and leave it sit for a minute or so. Anything to do to lessen this from occurring?