Please help with my 2007 Toyota Prius, No Mechanic has been able to help me. ! :-/

Well, it is true that lack of engine oil pressure will cause the master warning light to come on. However if you wait to see the light before you decide to add oil, you've allowed the engine to incur permanent damage. Further, as we've already discussed, there are many issues that might cause the master warning light to come on, not just lack of engine oil.

The catalytic converter failing does not cause the master warning light to come on because that issue by itself is not causing you or the car imminent damage. It is merely anti-social to be driving a vehicle that is producing more exhaust emissions than necessary.

It is very bad practice to continue to drive the Prius or any vehicle with warning lights on. Ideally you would determine the cause of each and effect necessary repairs. If your financial situation does not allow that, then you need to recognize that the car's mechanical condition will continue to degrade to the point where it will eventually leave you stranded.

 

... and probably cost you more in repairs in the long run.

 

A free/inexpensive thing that can be done to marginally improve the situation is to increase the tire pressure to max. sidewall and reset the TPMS (button on left side lower dash). If a tire pressure sensor has failed that idiot light will stay on until it is replaced. Placing a piece of electrical or painters tape over the tpms light will remove a distraction. I don't recommend taping over the other idiot lights as they are lit for a reason (many reasons).

I wish you good luck with the car but it won't last as long as you hope/expect/need it to.

 

this is what the OP pulled out of his stuck fan. Husky dog hair

 

You totally need an Automatic adapter or Carista adapter. It can track your trouble codes. That is the most unreliable Prius I've ever heard of. Good luck!

 

Smug test?

 

Yep, that's about it.
And if your primary goal is just to find a way to make the light go out, and continue to ignore problems, well there's more wrong with your ownership approach than the vehicle...and the vehicle might be in pretty bad shape.

 

The red triangle will come on for all kinds of *critical* reasons. If the oil falls below the level needed for the pickup, the pressure sender will go low and the red triangle will come on. If that's the reason, it means no oil pressure and you're engine is already ruined.

The yellow ECL will come on for a P0420 but not the triangle.

Also, you have to worry about smog now in California as your Prius needs to be smogged every other year now.