I need some help. Took my truck to O'Reilly Auto Parts store to find out why my check engine light was on. The trouble codes are p1131, p1151 and p0171. I don't have the money for a mechanic and I have been handy before with fixing things. Can someone give me some advice on how I might be able to fix this so I can get my vehicle to pass emissions.
The P1131 and the P1151 are 02 codes but the P0171 is a code that could cause the other codes to set. Check to see if the grommet under the air box where your MAF sensor plugs in has popped out. This happens when you change the air filter sometimes This causes a air leak in the intake system.
Good luck .
I don't care how handy you are , that's not going to help you unless you have knowledge of OBD 2 engine management system for your vehicle . Plus having diagnostic test equipment , scan tool to view engine sensor data ., an knowing how to do automotive electrical circuit testing.
Po171 Could be just an O2 sensor problem ,looking at scan data for bank 1 sensor 1 for proper switching , could be a easy find for a trained Tech . You on the other hand could spend hundreds an still not fix the problem .
P0171 - System to Lean (Bank 1)
The Adaptive Fuel Strategy continuously monitors fuel delivery hardware. The test fails when the adaptive fuel tables reach a rich calibrated limit.
For lean and rich DTCs:
P1130 - Lack of HO2S-11 Switch, Fuel Trim at Limit
The HEGO Sensor is monitored for switching. The test fails when the HO2S fails to switch due to circuit or fuel at or exceeding a calibrated limit.
A fuel control HO2S PID switching across 0.45 volt from 0.2 to 0.9 volt indicates a normal switching HO2S.
P1131 - Lack of HO2S-11 Switch, Sensor Indicates Lean
A HEGO sensor indicating lean at the end of a test is trying to correct for an over-rich condition. The test fails when the fuel control system no longer detects switching for a calibrated amount of time.
See Possible Causes for DTC P1130
P1151 - Lack of HO2S-21 Switch, Sensor Indicates Lean
A HEGO sensor indicating lean at the end of a test is trying to correct for an over-rich condition. The test fails when fuel control system no longer detects switching for a calibrated amount of time.
See Possible Causes for DTC P1130
006 O2 Sensor Signal Analysis
SOURCE: how do i fix emission codes p1131 p1151 p0171
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
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