Vehicle Losing Power When Accelerating

[BOB4254]

She's starving for fuel when I try to accelerate. Getting lean codes left and right banks.

These electric fuel pumps can become weak when they are on the way out.

Rail fuel pressure is low at 28-29 psi. should be 32-40 psi for a 5.4L engine.

I have a new BOSCH Fuel Pump with strainer on the way.

 

[1955moose]

A bad or malfunctioning tps switch will trip a p122 code. Your two codes are #1 and #4 cylinder malfunctioning. The changing of fuel filter and running right temporarily, leads to a fuel delivery issue. You might have a bad or malfunctioning new pump, along with clogged #1 #4 injectors. 28-45 psi is fuel pressure for your SUV. Your barely there. A fuel regulator usually will pump too high or leak when they go bad. I'd also look into plugged catalytic converter as a part of the problem. A shop can check if plugged. I'd start with what's causing #1 and#4 to act up. Try swapping coils #1 with #2 next to it and see if code moves. Do same with #4 Also pull and replace just those 2 spark plugs to see if codes go away or move. Report back what you find.