Service engine soon light

[Tonyray]

I have a 2000 Expedition 5.4 Eddie Bauer and the Service engine soon light came on I check the code and it's P0171 and P0174. I understand it's a bank 1 & 2 lean. I have replaced the PVC and hose. I though it must be what's wrong because it was taped all the way with black tape. So I put a new one on but still get the same code. I have cleaned the mass air flow sensor looked at all the vacuum hoses even replaced the fuel filter but I still get the same codes. Now it's getting hard to start and when you give it a little throttle it will try and die before it does rev the engine. So I'm thinking it might be a fuel pump issue. I'm going to get a fuel pressure gauge at Autozone tomorrow and see what the pressure is. Also going to buy a smoker tester to see if it's a vacuum leak.

 

[1955moose]

Well next step besides doing a fuel pressure test, is the Egr valve, and all the sensors and the port that must be clear. If it was me I'd do a smoking of the intake to be sure none of the hoses or gaskets are contributing to your problem. Also if you have any exaust leaks, they need to be repaired. They will give you a lean condition. The exaust manifolds are a problem with age.

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[BRIANGEE]

I think you're on the right track in checking the fuel pressure. Both banks lean simultaneously - I'd put money on a fuel delivery issue.

 

[1999]

I think you're on the right track in checking the fuel pressure. Both banks lean simultaneously - I'd put money on a fuel delivery issue.

I chased the same codes only to find out it WAS my fuel pump going bad...face palm.
I replaced my vacuum lines, O2 sensors, checked my coil packs
Do yourself a favor, next step check your fuel line pressure.

 

[1955moose]

That's why we always suggest that in any driveability problems! Surprising how few do. Must be that stinky gas smell!

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[Tonyray]

Thanks everyone for all the help. I checked the fuel pressure and with the ignition on engine off it's at 10 PSI running at is 20 psi and when it warms up 22 psi. I does drop a few pounds when I snap the throttle and acts like it's going to die but never goes higher then 22. My guess is fuel pump.

 

[stamp11127]

Either fuel pump or fuel filter. I'd change the pump due to age as a preventive measure. The fuel pressure, when running, should run 35 - 45 psi.

 

[1955moose]

Ditto.

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[Tonyray]

thanks I did change the filter a few weeks ago.

 

[Tonyray]

Dropped the tank today put the new pump in and went to take the pressure sensor out and of course it broke right off.