I have a 1999 Dodge Intrepid 2.7L and it recently threw a P0172 code. I replaced the oxygen sensor on the right bank sensor 1 and was fine until just a few days ago when the light came back on. I also have a hard time starting it like the fuel pressure regulator is bad. I am wondering if that code and the FPR are connected or if I just got a bad oxygen sensor.

 

could be bad sensor or leaky injector? i also had this issue and am having more issues ..