Kitchen sink OBD reading

[IngridRenee]

I have been pulling the same code for almost 6 months now. I replaced the gas cap, cleaned the MAF, and checked for leaks. I'm not sure what else to do that wouldn't require me to spend a lot of money troubleshooting. I haven't noticed my car driving any different or my gas mileage changing. If anyone can give me ideas I would appreciate it!

2015 Subaru Forester 2.5i Premium PZEV 2.5L 4cyl CVT

OBD Code: P0171

Warning lights that stay on:

Emission Control System

Hill Start Assist

Eyesight

Lane Assist

Check Engine

Vehicle Dynamics Control System warning

Due to the above, I can't use cruise control.