Dale thank you very much for your help

I have code P0170 with check engine light, I reset it with no luck.
Injector Leak or Vacuum leak or Pressure regulator.
I am not a mechanic, I will have a mechanic work on the car.
1- I would like to know how to test for Injector Leak and how much time require.
2-  test for vacuum leak, how much time is required, what value is good. what happened if they found a vacuum leak.
3- how to test for pressure regulator, what to look for.
4- how to test the MAF and O2.
5- anybody  had  problem with gas cap.
6- dealer do not recommended Techron, did any body use with no problem.
7- disconnecting the battery would  cause any problem with this car.