2001-2004 Ford F-150/250 MIL ON with DTC P1131 and/or P1151

MIL ON WITH DTC P1131 AND/OR P1151—4.2L ENGINE

FORD:

2001-2003 E-150, E-250, 2001-2004 F-150

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. 

ACTION Refer to the following Service Procedure. 

SERVICE PROCEDURE

1. 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.

2. 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. Refer to Workshop Manual, Section 303-01 (In-Vehicle Repair; Upper Intake Manifold) for removal and installation procedure.

3. 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. Download File PDF


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