None of the steps in the link I posted mention a reader.

But the reader can help you measure temperatures.

if it gets below 10% it's time to hit the gas station

 

OK so really this is all part of your other thread. I'm going to merge them for you.

 

ok so fuel input means the gas percentage on the tank I thought it was the percentage of fuel been used or thrown by the pcv selenoid

 

I don't think there is a such thing as a PCV "solenoid". The PCV sytem has nothing to do with fuel. It vents engine block pressure.
You're probably thinking of vent or purge solenoid valves, which are for the fuel tank and system.

 

yes my mistake purge selenoid sorry

 

Yeah a "level" is the height of a fluid.
Follow the steps Gumby gave you.

 

hello what is a normal evap pressure reading on a obd I'm having -1026 pa reading on the evap system vapor pressure

 

 

Yea I have a leak somewhere in the evap system

 

what's the diagnostic code?

look it up on obd-codes.com and follow the instructions there.

test the vent and purge valves, and smoke test the system.