Handykapper

My 1999 Lexus RX300 CEL light had come on. Went to Autozone and it was throwing a P0171 code. I replaced the MAF sensor and also check around for vacuum leaks. Reset the CEL and started diving the car. The light came back on but I continued to drive the car in case it needed to go through a couple of drive cycles. Now after 2 weeks of driving the car the light remains on. Not sure what would be the next best step to take. Any ideas or suggestions would be appreciated.