Po171 & Sometimes Po174
#1
09-10-2004, 06:11 PM
Po171 & Sometimes Po174
This is a great site
I have a 97 4.0 auto trani Ranger, ce light came on I replaced the before cat 02 sensors disconnected the bat. After 10 miles or so The light came on I pulled codes p0171 and po174 . Checked for vac leaks with starting fluid did not find any. cleard codes ran it, next time just p0171. checked egr was ok cleard code.
Ran it both 171 & 174 checked fule pressure cleard code and the last two times it has been just p0171.
Thank you for any help you may offer.
RTRC
I have a 97 4.0 auto trani Ranger, ce light came on I replaced the before cat 02 sensors disconnected the bat. After 10 miles or so The light came on I pulled codes p0171 and po174 . Checked for vac leaks with starting fluid did not find any. cleard codes ran it, next time just p0171. checked egr was ok cleard code.
Ran it both 171 & 174 checked fule pressure cleard code and the last two times it has been just p0171.
Thank you for any help you may offer.
RTRC
#2
09-10-2004, 07:24 PM
P0171 P0174 Lean Codes 1997 Ranger
Welcome to FTE!
Sounds like you are on the right track looking for vacuum leaks. Check all vacuum lines for deterioration, cracks etc., check for exhaust leaks before the 02 sensors, make sure your PVC system lines are secure and the valve is seated tightly.
You might also consider fuel deliver issues such as clogged fuel filter or injectors, for example.
A dirty or damaged MAF sensor can cause lean codes:
https://www.ford-trucks.com/forums/s...threadid=128532
Here is how to clean the MAF:
https://www.ford-trucks.com/forums/s...threadid=126093
Also, the '97 4.0Ls had a problem with fuel supply manifold gaskets, so you should also be aware of this Techinical Service Bulletin:
Sounds like you are on the right track looking for vacuum leaks. Check all vacuum lines for deterioration, cracks etc., check for exhaust leaks before the 02 sensors, make sure your PVC system lines are secure and the valve is seated tightly.
You might also consider fuel deliver issues such as clogged fuel filter or injectors, for example.
A dirty or damaged MAF sensor can cause lean codes:
https://www.ford-trucks.com/forums/s...threadid=128532
Here is how to clean the MAF:
https://www.ford-trucks.com/forums/s...threadid=126093
Also, the '97 4.0Ls had a problem with fuel supply manifold gaskets, so you should also be aware of this Techinical Service Bulletin:
Article No. 98-6-8
LIGHT TRUCK: 1997 RANGER, AEROSTAR
4.0L ENGINES ONLY
This TSB article is being republished in its entirety to correct the part number listed, revise the Service Procedure, and add Aerostar.
ISSUE:
A rough idle, stalling at an idle and/or Diagnostic Trouble Codes (DTCs) P0171, P0174, P1131, and/or P1151 may be stored in memory on some vehicles with a 4.0L engine. This may be caused by the gasket located between the fuel rail and lower intake manifold losing its compressive loading and becoming drawn into the intake manifold runners resulting in a vacuum leak.
ACTION:
Replace the fuel rail-to-intake manifold paper gasket with a revised gasket.
SERVICE PROCEDURE
1. Remove the upper intake manifold and inspect the O-ring style gaskets on the mounting surface of the upper intake manifold. If the gasket bead is above the intake surface and is not torn, do not disturb the gasket. If any of the O-ring gaskets are torn or do not protrude beyond the mounting surface of the upper intake manifold, the gasket should be replaced.
2. Remove six (6) studs and lift off fuel rail manifold and paper gasket.
3. Inspect all holes in the lower intake manifold to make sure there is no debris.
4. Replace the Gasket (F8PZ-9E436-AA) (bright green paper and blue bead) and set the fuel rail manifold on the gasket. No paper gasket is needed on the top side of the fuel rail manifold.
5. Lubricate the lower portion of the stud bolts with a light grade oil such as 5W30 and torque the bolts to 14 ±2 Nm (10 ±1.5 lb-ft)
6. The upper intake manifold should be installed and the nuts torqued to 25 Nm (18.5 lb-ft)
7.Start and warm the engine.
8. Allow the engine to cool and retorque all of the nuts to 25 Nm (18.5 lb-ft).
PART NUMBER / PART NAME
F8PZ-9E436-AA / Fuel Rail-To-Intake Manifold Gasket
OTHER APPLICABLE ARTICLES:
NONE
SUPERSEDES:
97-20-10
WARRANTY STATUS:
Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage And Emissions Warranty Coverage
LIGHT TRUCK: 1997 RANGER, AEROSTAR
4.0L ENGINES ONLY
This TSB article is being republished in its entirety to correct the part number listed, revise the Service Procedure, and add Aerostar.
ISSUE:
A rough idle, stalling at an idle and/or Diagnostic Trouble Codes (DTCs) P0171, P0174, P1131, and/or P1151 may be stored in memory on some vehicles with a 4.0L engine. This may be caused by the gasket located between the fuel rail and lower intake manifold losing its compressive loading and becoming drawn into the intake manifold runners resulting in a vacuum leak.
ACTION:
Replace the fuel rail-to-intake manifold paper gasket with a revised gasket.
SERVICE PROCEDURE
1. Remove the upper intake manifold and inspect the O-ring style gaskets on the mounting surface of the upper intake manifold. If the gasket bead is above the intake surface and is not torn, do not disturb the gasket. If any of the O-ring gaskets are torn or do not protrude beyond the mounting surface of the upper intake manifold, the gasket should be replaced.
2. Remove six (6) studs and lift off fuel rail manifold and paper gasket.
3. Inspect all holes in the lower intake manifold to make sure there is no debris.
4. Replace the Gasket (F8PZ-9E436-AA) (bright green paper and blue bead) and set the fuel rail manifold on the gasket. No paper gasket is needed on the top side of the fuel rail manifold.
5. Lubricate the lower portion of the stud bolts with a light grade oil such as 5W30 and torque the bolts to 14 ±2 Nm (10 ±1.5 lb-ft)
6. The upper intake manifold should be installed and the nuts torqued to 25 Nm (18.5 lb-ft)
7.Start and warm the engine.
8. Allow the engine to cool and retorque all of the nuts to 25 Nm (18.5 lb-ft).
PART NUMBER / PART NAME
F8PZ-9E436-AA / Fuel Rail-To-Intake Manifold Gasket
OTHER APPLICABLE ARTICLES:
NONE
SUPERSEDES:
97-20-10
WARRANTY STATUS:
Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage And Emissions Warranty Coverage
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