2001 RX 300 Low Oil Light and P1351 after engine work

[Vesperia]

I have been working on an RX 300 for a bit now. I did the valve cover gaskets, new Denso spark plugs, new oil pan, replaced transmission fluid and filter (was slipping). Also replaced both OCV's (more on that later).

After finding that I had not grounded the rear plenum ground (which caused a whole host of issues), the car was running and driving great! 

I took it for a drive around my back road and it was driving fine. I turned off and then on the overdrive for the transmission (just to check it worked) and the low oil light came on. This was a similar symptom / issue I had before I replaced the oil pan and cleaned out the pick up tube. It has the correct amount of oil and a new filter. After driving it for a bit with the low oil light on the car died while driving and the dash lit up. I pulled over, turned the car off, and started it back up and it was fine. About 30 seconds later the low oil light came on again but I was able to make it to my drive way and park it without issue.

Currently the only code showing up is the P1351 which is the OCV I replaced on the front bank with a junkyard denso part. I have a new NGK OCV I am going to swap with it to see if the error code goes away. 

Still stumped on the low oil light though after turning off and on the overdrive on the transmission. Could a bad OCV cause the low oil light to turn on?

Thanks!

[Vesperia]

Bleep blorp, I replaced the oil pressure sensor with a new one and will do the same route with turning off O/D while at 60 MPH to see if I can replicate the issue. If it happens again I am going to drop the oil plan and take out the pickup and clean it out instead of just cleaning the screen like I did last time and do the same route. 

[Vesperia]

More fun! After replacing the oil pressure sensor I did not have the low oil light pop up, however I also did not do the O/D off and on to see if it would trigger. Going to try that again this weekend.

However more codes showed up!

Current list:

P0125 - Several reports say this is related to the O2 sensors. I am going to check all the wiring and make sure they're plugged in and then possibly replace the O2 sensors if that does not fix it.

P1130 - Rear bank air fuel / O2 sensor needs to be replaced... hmm this is interesting... 

P1133 - Upstream O2 sensor is bad... well another O2 sensor, wonder if they used non-denso parts. Going to clean the MAF and see if it helps.

P1153 - Yet another O2 / Air fuel sensor. This is interesting! Definitely going to check for vacuum leaks as well as the current O2 sensors. 

P1351 - I have gone through roughly 3 different sensors, one OEM Denso from a junkyard, one NGK, and one generic from Amazon. I think the engine may be slightly out of time and it's due for a timing belt replacement so that may fix the issue.