P0172 help

Question

Currently have a P0172 DTC on my 2000 mazda protege dx 1.6l. I have replaced upstream 02 sensor, MAF sensor,  spark plugs, plug wires and fuel pump, fuel filter and I'm still getting the code
 The car starts right up Although typically in the mornings when I first start the car it will start to surge and nearly shut off but it doesn't. I've also replaced the fuel injectors with some used injectors from a junkyard. Usually after about 15 mins of driving in the mornings the car runs as it should but when sitting in traffic or stop and go traffic it begins to surge again. The check engine light will randomly turn off and come back. I also can't use the a/c or the car will either surge, shut off or when I accelerate there is a huge lack of power and the car will not want to accelerate.

Answer 1

This engine has a fuel pressure regulator , check the vacuum hose port to the fuel pressure regulator , if that regulator is seeping fuel , replace the fuel pressure regulator.