P131B Diagnostic Trouble Code

P131B is a kind of OBD-II Diagnostic P-Powertrain Diagnostic Trouble Code.

It is considered generic because it applies to all makes and models of vehicles, although specific repair steps may be different depending on your car model.

Symptoms

Symptoms of a P131B diagnostic trouble code may include:

Cherry red hot catalytic converter
Poor acceleration
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.
Engine surge

Possible Causes :

Rarely - faulty Powertrain Control Module (PCM-programming required after replacement)
Rough running engine due to misfiring plugs. Many engines have misfire codes to indicate the cylinder effected, such as P0307 for number 7.
An air leak forward of the DPF will change the sensor readings resulting in the code

Repair Processes :

With the valve disconnected, the red voltmeter lead should be attached to the IMRC valve power wire and the black voltmeter lead connected to ground. If the scan tool has that capability, and the scan tool can operate the IMRC valves, then the problem is either resolved and a simple code clearing is all that's left or a new PCM would be called for. Replace the oxygen sensor that is downstream from the catalytic converter on the side of the engine that does not contain cylinder #1. Also, if a oxygen sensor code stating "heater circuit malfunction" the sensor has most probably failed.

Process Tips

Diagnostic trouble code P131B is not difficult to diagnose and repair. Thus, it always pays to have a qualified technician to look after your vehicle should this error code arise.

Diagnosing this code requires the engine to be in good running shape, without unmetered air entering the engine. If other codes that relates to misfiring condition, lean running or air entering the engine is present, then you must first fix those error codes before P131B.

Fortunately, P131B is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

P131B Trouble Code For Specific Cars

P131B Citroen 2cv First Gear Switch Circuit Malfunction
P131B Matra M530 Transmission Neutral Safety Switch Open Circuit
P131B Alfa Romeo Sz Air Bag Crash Sensor #2 Ground Circuit Open
P131B Oldsmobile Six Damper LF Circuit Short To Battery
P131B Mg Tb Alarm Panic Input Circuit Short To Ground
P131B Lancia Flavia Speed Wheel Sensor Rear Center Input Circuit Failure
P131B Alfa Romeo 20 ABS Power Relay Output Short Circuit To Ground