codes 1131, 1151
Thread Starter
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Member
Joined: Mar 2007
Posts: 40
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From: Rochester, NY
codes 1131, 1151
2002 F150
4.2V6
65,000 miles
I have been getting the same two codes for the past few months almost as soon as winter started (1131 and 1151) I have:
Checked for vacuum leaks
Replaced air filter
checked oil level
Replaced both upstream O2 sensors
Every time I clear the codes they return within a couple of driving cycles.
Can anyone tell me what the most common cause is for these two codes two appear. I have heard the Manifold gasket being worn can cause these codes to appear, but that is something I don't want to be tackiling in the dead of winter. As of yet I have not noticed any proplems with performance, just the nagging codes.
Thanks,
Geoff
Anything information would be a big help.
4.2V6
65,000 miles
I have been getting the same two codes for the past few months almost as soon as winter started (1131 and 1151) I have:
Checked for vacuum leaks
Replaced air filter
checked oil level
Replaced both upstream O2 sensors
Every time I clear the codes they return within a couple of driving cycles.
Can anyone tell me what the most common cause is for these two codes two appear. I have heard the Manifold gasket being worn can cause these codes to appear, but that is something I don't want to be tackiling in the dead of winter. As of yet I have not noticed any proplems with performance, just the nagging codes.
Thanks,
Geoff
Anything information would be a big help.
Technical Article Contributor
Joined: Jan 2007
Posts: 10,636
Likes: 264
From: Vernon, NY
Check into this issue.
TSB
05-22-6
ISSUE:
Some 2001-2003 F-150, 2004 F-150 Heritage and 2001-2003 E-150/250 vehicles equipped with a 4.2L engine may exhibit the malfunction indicator lamp (MIL) on with diagnostic trouble codes (DTCs) P1131 and/or P1151 (system too lean bank 1 or 2). This condition may be due to leaking isolator bolts/port gaskets in the upper-to-lower intake manifold mounting area. This condition is sometimes intermittent and may not be apparent on a warmed-up engine.
SERVICE PROCEDURE
Perform a self test. If DTC P1131 and/or P1151 are the only codes stored in the powertrain control module (PCM) proceed to Step 2. If any additional DTCs are present, follow normal diagnostic procedures found in the PC/ED Manual.
Remove the upper intake and replace only the port gaskets (9H486) and isolator bolt assemblies (9S479). The new isolator bolt assemblies use a rubber material that is green in color, do not install the old isolator bolt assemblies with the black rubber material. Do not replace any other intake parts or gaskets.
While the upper intake manifold is removed, check the exhaust gas recirculation (EGR) orifices that are pressed into each primary port of the lower intake manifold. If any of the orifices are plugged with soot, clean and unplug them with a pick and solvent.
PART NUMBER PART NAME
1L3Z-9H486-AA Port Gasket
3F2Z-9S479-AA Isolator Bolt
Even tho it says just to replace these parts id also be tempted to change the lower intake gaskets as well while your in there.
TSB
05-22-6
ISSUE:
Some 2001-2003 F-150, 2004 F-150 Heritage and 2001-2003 E-150/250 vehicles equipped with a 4.2L engine may exhibit the malfunction indicator lamp (MIL) on with diagnostic trouble codes (DTCs) P1131 and/or P1151 (system too lean bank 1 or 2). This condition may be due to leaking isolator bolts/port gaskets in the upper-to-lower intake manifold mounting area. This condition is sometimes intermittent and may not be apparent on a warmed-up engine.
SERVICE PROCEDURE
Perform a self test. If DTC P1131 and/or P1151 are the only codes stored in the powertrain control module (PCM) proceed to Step 2. If any additional DTCs are present, follow normal diagnostic procedures found in the PC/ED Manual.
Remove the upper intake and replace only the port gaskets (9H486) and isolator bolt assemblies (9S479). The new isolator bolt assemblies use a rubber material that is green in color, do not install the old isolator bolt assemblies with the black rubber material. Do not replace any other intake parts or gaskets.
While the upper intake manifold is removed, check the exhaust gas recirculation (EGR) orifices that are pressed into each primary port of the lower intake manifold. If any of the orifices are plugged with soot, clean and unplug them with a pick and solvent.
PART NUMBER PART NAME
1L3Z-9H486-AA Port Gasket
3F2Z-9S479-AA Isolator Bolt
Even tho it says just to replace these parts id also be tempted to change the lower intake gaskets as well while your in there.