P0171 & P0174

Hello,
I have a 2002 Sport Trac 4.0 with 148k miles. Over the last couple of months I keep getting the P0171/0174 codes. Reset with scan tool and it's fine for about a week and a half then back again.

After doing a little research on this forum I think it is likely to do with the fuel filter needing replaced. (I do recall only getting the codes when running low on gas as well which further leads me to believe it's the filter)

No vacuum leaks, new DPFE etc...

My concern is that I have been told by a couple of different people that many times after a fuel filter that hasn't been replaced in a while is changed, the fuel pump is very likely to fail shortly after.

Does anyone know if there is any truth to this?

Thanks in advance

A plugged fuel filter will make the fuel pump work harder. I think if it fails it was running low on gas which overheats the pump and a blockage made it work a lot harder. The longer it goes if partially plugged the more likely the pump will fail.

Changing the filter will not cause the pump to fail. As rhandwor has stated, the pump will not work harder. And he is correct on the heat due to low fuel. These are things that will cause premature pump failure. Change the filter and let us know the outcome. If the otiginal pump has lasted 148K, then it deserves a rest. If it fails, you still have nothing to complain about. We replace pour pumps under 100k on about all out vehicles due to pump failure.

Thanks, I appreciate the responses. Everything said makes good sense. I'll report back after the filter replacement.

those codes are usually pointing int he direction of intake gasket, or maybe just o2 sensor

Also verify that the hoses to the DPFE were not connected backwards when installed.

-Rod

check the rubber elbow connected to plastic pipe just behind and left of throttle body for a hole or softness.