My 88 305 TBI has some issues:

First my oil pressure is erratic. It will be fine driving it for half an hour to a whole day then it will gradually fall to just above the red. ive pulled over checked the oil level and everything and the pressuer will go back up and drop again later I keep the oil filled and it has small oil leak.

check engine light. could be because of the oil pressure but the light dosnt always come on when the oil pressure drops. It will come on randomly driving stay on for any where from 5 min to half an hour and when i borrowed a computer and plugged it in (did this 3 times and forgot to write down what it said....i know dumb) it said somethin about the air intake

jus wondering if anyone had any ideas before i spend the money to take it to a mechanic

 

have you done a pressure test? disconnect the the wire to the oil pressure sending unit and see if it has oil, it should be dry

 

The oil pressure isn't erratic, the sender is. Just replace it.

The check engine light is a different issue that has nothing to do with the oil pressure sender.

 

On the engine light .... Pull the codes for your check engine light!

Grab a paperclip and read: https://www.thirdgen.org/service-eng...ht-error-codes

On the oil pressure, try a new sender like mentioned. It's located above oil filter, about $30.