Why does my engine light keep coming on, code reader dispays codes 171

Is the full code P0171? If so that indicates a lean fuel mixture, which can be caused by lots of different things. I would start by checking for a vacuum leak, check for loose or dry-rotted hoses. Clean the Mass AirFlow sensor with the appropriate cleaner and see if your problem persists. If so, check your fuel pressure, if it is too low you will need to determine the cause. If your fuel pressure is correct, the problem is possibly a stuck EGR valve. Let me know what you find and I’ll try to help guide you further. I hope this helps and good luck with your repair!