Low oil pressure came on yesterday. knocking noise. Sometimes it goes off.

I used motor-craft synthetic blend. I only added 2 qts because I had more at home and it was reading low pressure. It was a little low I guess. I haven't added more yet because someone mentioned that it may be the oil pump. But it may also be something with the switching out of the sensors on the camshaft and crank-shift.

Don't overfill your oil. Check the connection to the oil sending unit. If it's not knocking when low pressure indicated, I would replace the oil sending unit. Many times they go bad, and your oil pressure is fine. ALWAYS CHECK OIL LEVEL BEFORE ADDING.

Thanks, did check oil and oil level is fine, however the oil pressure gauge is on low.

Check connection and/or replace the sender, it's usually behind the oil filter. Make sure it's not leaking as well since you were also low on oil.

Thanks,