oil pressure way to low and good chance if its been driven any amount of time that the bearing will have been damaged.

This unless of course ya gauge is faulty have you been to a garage and got them to check it with a external gauge?

same thing happened to me before i rebuild engine in BMW when i took bigend off they where just about worn threw

it was me i'd have the sump off remove all bigends and meassure the crank as long as it's not picked up on the crank and they meassure true replace bigends and fit some ARP bolts.

also while ya in there check and measure the Mains also these tend to suffer less put double check them and be sure

I got my oilpump off Matt Lewis High Pressure 5 bar pump
when at warm idle it show no less than 1.8bar as soon as its rev'd up it climbs to 4.5bar+

Pic of pump