thanks for the info! Think I might just try to replace the oil pressure sensor and install a pressure guage as well using a T-splitI used to know the factory Toyota switch but my memory is fading. Most oil switches I have come across for US and Japanese makes are 5-7 psi. But if you have 5psi at 4000rpm, the engine will not last very long. Rule of thumb is 10psi per 1000rpm. So what I would do is monitor where your oil pressure normally sits fully warmed up and hot engine. Then subtract 2-4psi and set your light there. If your engine idles at 17psi, then turn the light on at 15psi. That will provide you a little more warning time than the factory light. If you get flickering light, you might need to lower the warning lamp. It all depends on how much the oil pressure fluctuates due to oil pump wear and the pressure relief spring.
Not sure if this is needed anymore, but a OEM 5th Gen oil pressure switch has a switching pressure of 4.3 psi, per the factory service manual.Anyone know the exact psi the light is supposed to come on, I'm swapping my sensor for a dual guage/light, and I'm trying to figure out what psi the gauge should be set at to spark the light, thanks.