Working to get rid of the P0171 code. So far, no vacuum or exhaust leak. Replaced the upstream O2 sensor. The code is still there. The mechanic says for sure it's the fuel pressure regulator. I need some help on a video or some sort of good instructions to see if I could do it myself. The mechanic wants $350 to do the job and guaranteed the code will go away. I wonder if I could do it myself to save some money.