P0171 code
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Junior User
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P0171 code
I've got a 2000 Ford Ranger 2.5. Keep getting a code of P0171.
I have changed the fuel filter, maf sensor ,PCv and 2 vacuum hoses,
Checked for vacuum leaks. Plugs and wires. Still getting the code. Any suggestions on what i should do next? Fuel pressure is a@ 65 psi
I have changed the fuel filter, maf sensor ,PCv and 2 vacuum hoses,
Checked for vacuum leaks. Plugs and wires. Still getting the code. Any suggestions on what i should do next? Fuel pressure is a@ 65 psi
Cargo Master
Joined: May 2004
Posts: 3,007
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P0171 Ststem to Lean
The adaptive fule strategy continously monitors fuel delivery hardware. The test fails when the adaptive fuel tables reach a rich calibrated limit.
Possible causes
Fuel system
Excessive fule pressure
Leaking/contaminated fuel injictors
Leaking fuel pressure regulator
Low fuel pressure or running out of fule
Vapor recovery system
Induction system: including Air leaks after the MAF, Vacuum Leaks, PCV system, Improperly seated engine oil dipstick
EGR system: including Leaking gasket, Stuck EGR valve, Leaking diaphram or EVR
Base engine; including oil overfill, cam timing, cylinder compression, exhaust leaks before or near the HO2Ss.
So Check the intake air system for leaks, obstructions and damage
Check air cleaner element, air claner housing for blockage
Verify integrity of the PCV system
Check fuel delivery system and filter for restriction
Check for vacuum leaks.
The adaptive fule strategy continously monitors fuel delivery hardware. The test fails when the adaptive fuel tables reach a rich calibrated limit.
Possible causes
Fuel system
Excessive fule pressure
Leaking/contaminated fuel injictors
Leaking fuel pressure regulator
Low fuel pressure or running out of fule
Vapor recovery system
Induction system: including Air leaks after the MAF, Vacuum Leaks, PCV system, Improperly seated engine oil dipstick
EGR system: including Leaking gasket, Stuck EGR valve, Leaking diaphram or EVR
Base engine; including oil overfill, cam timing, cylinder compression, exhaust leaks before or near the HO2Ss.
So Check the intake air system for leaks, obstructions and damage
Check air cleaner element, air claner housing for blockage
Verify integrity of the PCV system
Check fuel delivery system and filter for restriction
Check for vacuum leaks.
New User
Joined: Jun 2009
Posts: 6
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My 2003 3.0 had the same code. After trying all of the previous suggestions, I found that there were two computer updates since my purchase. This was at about 50,000 miles, re flashed computer and now at 72,00 miles there has been no re-occurrence.
Postmaster
Joined: Oct 2009
Posts: 3,432
Likes: 7
I would look at that computer update, but you can still have undetected leaks. It is not uncommon for the upper or lower intake gaskets to start leaking as they dry and shrink. Leaks in these gaskets can often be hard to detect other than from the resulting lean code. If you can have your system checked with a smoke machine, that would probably rule leaks out. Its either that or you could chance just replacing the gaskets.
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Junior User
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Code P0171
Ok thanks everybody. I think I will have it smoke tested before i do anything else.
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Fleet Mechanic
Joined: Feb 2007
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From: Boston, MA
do you have more details about the fuel pressure test I know you said 65 but what was the koeo p;ressure and how many cycles to get there. what was the koer and how much did it drop in 5 minutes after the truck was turned off
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P0171
65 psi at idle 1 cycle koeo was 35 psi
here's the freeze frame data
fuel system 1 closed loop
calc load 49.0
coolant temp 179
stft -2.3
ltft 25.0
rpm 2029
vehicle speed 50 mph
I erased the KAM after putting on the MAF sensor and fuel filter. Code still came back about 20 miles later.
here's the live data
fuel system 1 status CL
calc load value 29.41
coolant temp. 87.00
stft bank 1 -0.78
ltft bank 1 2.34
rpm 952.25
vehicle speed sensor 0.00
ignition timing advance #1 cylinder 6.50
air intake sensor 69.00
air flow rate for maf 4.06
absolute throttle position 17.25
bank 1 sensor 1 0.76 v
bank1 sensor 1 -2.34%
bank 1 sensor 2 0.82 v
hope this is helpful
here's the freeze frame data
fuel system 1 closed loop
calc load 49.0
coolant temp 179
stft -2.3
ltft 25.0
rpm 2029
vehicle speed 50 mph
I erased the KAM after putting on the MAF sensor and fuel filter. Code still came back about 20 miles later.
here's the live data
fuel system 1 status CL
calc load value 29.41
coolant temp. 87.00
stft bank 1 -0.78
ltft bank 1 2.34
rpm 952.25
vehicle speed sensor 0.00
ignition timing advance #1 cylinder 6.50
air intake sensor 69.00
air flow rate for maf 4.06
absolute throttle position 17.25
bank 1 sensor 1 0.76 v
bank1 sensor 1 -2.34%
bank 1 sensor 2 0.82 v
hope this is helpful
Fleet Mechanic
Joined: Feb 2007
Posts: 1,716
Likes: 0
From: Boston, MA
Koeo should be 60 and it should get there within a few cycles
Fleet Mechanic
Joined: Feb 2007
Posts: 1,716
Likes: 0
From: Boston, MA
Koeo=key on engine off
Koer=key on engine running
Cycle=turning key on and off
If your koeo is not about 60 after 2 or 3 cycles something is wrong
Pressure should not drop more than about 8psi in 5 minutes after koer test
Did you put the fuel filter in the right direction?
Add some Techron to the tank
Koer=key on engine running
Cycle=turning key on and off
If your koeo is not about 60 after 2 or 3 cycles something is wrong
Pressure should not drop more than about 8psi in 5 minutes after koer test
Did you put the fuel filter in the right direction?
Add some Techron to the tank
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