2003 4Runner V6 Check oil light problem! Need some help!

I drove on a 600 mile round trip to oklahoma this weekend but on the way there I passed a guy and then as I was slowing back down from passing him my check oil light came on. I pulled over and then checked my oil and the level was perfect. I turned my T4R back on and... no check oil light so I headed on my way. About 25miles down the road I came to a town and the speed limit went from 65 to 35 and as I was slowing down, my check oil light came on again. I pulled over and checked once again and it was still good. I proceeded to buy a quart of oil and I put 1/2 a quart in and started it back up and.. no oil light. I went the next 300 miles and no check oil light and it was fine. My truck sat for 3 days then I came home and I never saw the light come on again until about 30 miles from home when I passed a guy and started slowing down again and my light came on again and my oil was still good. It stayed on the rest of my way home and when I pulled in the drive way I heard a slight knock so I shut it down right away and I started it back up and my oil light was off and no knocking at all. What the heck is going on? My first guess would be my oil pump going bad but I really have no clue. Any help would be awesome because I don't want to put one more mile on it and risk damaging something. My T4R is an 2003 limited with 113k miles with the V6 if that helps any. Thank you for your help!

 

oil pump!!!

DO NOT drive it until you replace it.

 

u need to put anoil pdessure gauge on it......