98 intermittent oil light/beep question

I bought a 1998 beetle a couple months ago (gas, non-turbo 2.0 automatic). I noticed the check engine light was lit, but everything seemed normal with the engine (I know a lot of times it's just a bad sensor). I didn't experience any problems because I usually just drive it to work or in town for 15 mins or so. But I took it out of town a couple weeks ago and it seems once it gets warmed up good and then if you slow down the RPM for a stop light or whatever, the red oil light comes on for a few seconds and it beeps 3 times. As soon as I get it back up over 2500 or so RPM it's fine, but if you slow back down it usually gives me the beep/light again. I got an oil change to make sure it wasn't just some debris or filter, but it still does it if I drive for more than 20 mins or so. There is no heat light warning, and it has plenty of oil and coolant of course.

I know I should probably run the diag to get what computer code the check engine light is telling, but I was just asking here before I get it checked out in case there's a known issue with this or something. I'm thinking maybe just a bad sensor, or maybe the oil pump is going bad? Only has 68k miles. It still runs the same either way. Just thought I'd ask you guys before I try to tackle the issue. Thanks!

I would reccomend just replacing the high and low pressure oil switches (there only about 13.00 each)