After clearing codes I get repeat P0171 and P0174 codes on warm and cold engine after running for over 30 minutes?

 

Both banks are running lean. How many miles on your engine, when was it last tuned along with wires, when did you last clean/replace your air filter?
Check for vacuum leaks.

 

If you get 0733,0734 then its a maf sensor, Look for vacuum leaks such as hoses or blown out intake gaskets. Oh and check fuel trims. Its also possible you have a small leak in the exhaust but usually not both banks.