Ordinarily , we would be prompted to try swapping out a sending unit as I did not too long ago and it read better but didn't help much to increase pressure but I had to know if the reading was correct. That little sensor was pricey and before we ask you to drop some cash on it , I'd like to make a suggestion. Look for the complete o-ring kit for the oil filter adapter housing and install that to see if oil pressure improves . It's a three piece kit and it not only seals any outside leak but any internal leak as well . There's the papa o-ring , mama and baby that all help toward getting oil from the pump , through the filter and through the oil passages at adequate pressure.
When I pulled my housing apart on an oil change , I found that the baby o-ring was loose and brittle on the center bolt which is hollow and controls pressure between bypass and main oil galleries . When you pull yours apart , you will see how each o-ring plays its part in helping to keep pressure and not just letting it bypass . It's an easy fix and not expensive but necessary as we know how important oil pressure is. The only tough part is that center hollow bolt is tight so be prepared to fight with it but don't let it get the best of you and cause any carnage . It's probably real easy for something to go wrong here but be cool and you'll get it loose .
Mine has a cast hex nut which makes it easy to grab but I heard some have a internal hex or torx that can be cause for using restraint when we find out how tight they are . I guess it's just the nature , hot oil under pressure gets all over the parts internally and cools down and sticks like glue , especially on the threaded part of the hollow bolt your trying to unthread from the block.
I know your not scared and definately not green but I thought I would help prepare you for the moment because when I did it , I thought I was going to back in the house in 45 minutes or less but it fought me and caused me to decide what weapon of choice to fight back with . Funny though , you would think an in -line six should be easier to access ( they once were ) but two things on a cherokee , alternator and this oil filter adapter . Well , go in with a plan and don't underestimate your enemy . Curious to know if this will help the pressure . Long winded post for just three little o-rings huh ? Don't worry brother , you the man . You'll get it . Got my faith .
