So I have tried to find a cure for this and right now I feel like I am just throwing parts at the car. I am getting a P0171 Fuel Trim System Lean Bank 1 code on and off again.
So far I have replaced the stock injectors with rebuilt flowmatched ones from ZZP. I have changed the fuel filter. I have changed the fuel regulator. I have changed the two fuel pump relays. I have bent the one pin on the outer relay out to make the pump stay in "high" mode. I have changed the MAF. I have changed the MAP. I have replaced all of the vacuum line with new rubber line. I have tested the fuel pressure. It is 41-42 normal and with the vacuum line from the fuel pressure regulator pulled it goes up to a steady 50.
The code is intermittent and usually only comes on when the car is coasting, at idle or bearly above idle. When I'm pressing on the gas more than a little bit, then it doesn't come on. Yeah, I know. Just keep it to the floor, but seriously I need help fixing this. I have a new AC Delco pump coming to me and a high flow fuel filter on the way also, just in case.
Any knowledge, thoughts, or enlightenments would be greatly appreciated.
For the sake of getting help, I have a 99 GTP 3.8 Supercharged stock.
Thanks again in advance.