Code P1131 (pd)


Asked by Jan 06, 2016 at 04:40 PM about the 2002 Mercury Sable LS

Question type: Maintenance & Repair

Car just sputtering code P 1131 (pd)

2 Answers


Possible causes p1131:>--- - Faulty Upstream Oxygen Sensor Bank 1 - Fuel pressure high or low - MAF sensor dirty/defective - Vacuum leak on engine - Leaking fuel injector or fuel pressure regulator - Faulty Powertrain Control Module (PCM) What does this mean? What does this mean? Tech notes Though the Oxygen (O2) sensor, the Engine Control Module (ECM) has detected a lean system, which means that there is either not enough fuel or and excessive amount of air in the system. Start by checking for vacuum leaks. When is the code detected? When an HO2S sensor indicates lean at the end of a test, the system is trying to correct for an over-lean condition. The code is set when the fuel control system no longer detects switching for a calibrated amount of time. Possible symptoms - Engine Light ON (or Service Engine Soon Warning Light) P1131 Mercury Description The Heated Oxygen Sensor (HO2S) Monitor is an on-board strategy designed to monitor the HO2S sensors for a malfunction or deterioration that can affect emissions. Under specific conditions, the fuel control or upstream HO2S sensors are checked for proper output voltage and response rate (the time it takes to switch from lean to rich or rich to lean). Downstream HO2S sensors used for Catalyst Monitor are also monitored for proper output voltage. Input is required from the Engine Coolant Temperature (ECT) or Cylinder Head Temperature (CHT), Inlet Air Temperature (IAT), Mass Air Flow (MAF), Throttle Position (TP) and Crankshaft Position (CKP) sensors to activate the HO2S Monitor. The Fuel System Monitor and Misfire Detection Monitor must also have completed successfully before the HO2S Monitor is enabled. • The HO2S sensor senses the oxygen content in the exhaust flow and outputs a voltage between zero and 1.0 volt. Lean of stoichiometric (air/fuel ratio of approximately 14.7:1 for gasoline engines), the HO2S will generate a voltage between zero and 0.45 volt. Rich of stoichiometric, the HO2S will generate a voltage between 0.45 and 1.0 volt. • The HO2S Monitor evaluates both the upstream (Fuel Control) and downstream (Catalyst Monitor) HO2S for proper function. • Once the HO2S Monitor is enabled, the upstream HO2S signal voltage amplitude and response frequency are checked. Excessive voltage is determined by comparing the HO2S signal voltage to a maximum calibratable threshold voltage. • A fixed frequency closed loop fuel control routine is executed and the upstream HO2S voltage amplitude and output response frequency are observed. A sample of the upstream HO2S signal is evaluated to determine if the sensor is capable of switching or has a slow response rate. • An HO2S heater circuit fault is determined by turning the heater on and off and looking for a corresponding change in the OSM and by measuring the current going through the heater circuit. • The MIL is activated after a fault is detected on two consecutive OBD II drive cycles.

3 out of 3 people think this is helpful.
Best Answer

Thank you very much, need to ask rear 02 sensor able to do without taking off manifold. Looks like can do this from bottom or top.

Your Answer

Add photo

Related Questions

  • Fuse box 6 answers

    My car got stolen but has been found and returned home its an 83 mercury Capri 5.0. The fuse box was cut out by the culprits where can I get a new one? How hard is wirring it in? What cars have th...

    1983 Mercury Capri


    Maintenance & Repair

  • PASSAT TDI-PD 2003 2 answers


    2003 Volkswagen Passat


    Maintenance & Repair

  • Getting a code P0442 and P0442 pd after my car stalled out going down the road and had to tow it home. 2 answers

    Not sure if it matters, but we just put new exhaust on and replaced both CV shafts. After we got it all fixed it ran fine, I filled up car (first time totally filling it since I bought it, was only s...

    1999 Pontiac Grand Prix 4 Dr GTP Supercharged Sedan


    Maintenance & Repair

  • if i change just the brakes pds in a chevy 05' 1500 siverado, do i vave to reset de computer ? 4 answers

    the engine doesn't star after replaced just the brake pads and the check engine light appear at the dash board !!! Do I have to reset the computer ??

    2005 Chevrolet Silverado 1500 LS Long Bed 2WD


    Maintenance & Repair

  • 06 Taurus Misfire Dark Smoke, Engine Light On, 9 Codes 1 answer

    I have a 06 Taurus SE, 3.0L 12v, Engine Code U. 40K miles. Bought at 27K miles. A few days ago, I drove 3 miles to a store, turned off the engine and this happened. It will start, but the engine vibr...

    2006 Ford Taurus SE


    Maintenance & Repair

Search Mercury Sable Questions

Mercury Sable Experts

#1 JP1956
Reputation 550
#2 Tom Demyan
Tom Demyan
Reputation 450
#3 Guy Outland
Guy Outland
Reputation 360
View All

Related Models For Sale

Used Ford Taurus"
360 Great Deals out of 23,103 listings starting at $1,400
Used Ford Mustang"
725 Great Deals out of 41,064 listings starting at $900
Used Honda Accord"
1,254 Great Deals out of 78,695 listings starting at $1,400
Used Mercury Grand Marquis"
44 Great Deals out of 2,557 listings starting at $1,300
Used Honda Civic"
1,145 Great Deals out of 59,092 listings starting at $995
Used Nissan Altima"
1,340 Great Deals out of 87,462 listings starting at $1,095
Used Chevrolet Impala"
935 Great Deals out of 35,693 listings starting at $1,500
Used Mercury Mountaineer"
31 Great Deals out of 1,686 listings starting at $1,950
Used Toyota Camry"
1,580 Great Deals out of 98,373 listings starting at $895
Used Nissan Maxima"
496 Great Deals out of 24,224 listings starting at $1,500
Used Ford F-150"
3,257 Great Deals out of 216,652 listings starting at $1,500