P1133 - FAULT CODE - OBD2

P1133 Code failures by brands

P1133 ACURA, BUICK, CADILLAC, CHEVROLET, GM, HONDA, ISUZU, PONTIAC, SATURN: INSUFFICIENT SWITCHING SENSOR HO2S 1

P1133 DAEWOO: AT FUEL SOLENOID FAILURE

P1133 FIAT: B1-S1 OXYGEN SENSOR

P1133 LEXUS: AIR/FUEL RATIO SENSOR CIRCUIT RESPONSE FAILURE BANK 1 SENSOR 1

P1133 MERCURY, OLDSMOBILE, LINCOLN, JAGUAR: BANK 1 FUEL TRIM CONTROL

P1133 VOLKSWAGEN, AUDI, VOLVO: ELECTRICAL MALFUNCTION OF THE O2 SENSOR HEATING CIRCUIT BANK 1 SENSOR1

P1133 TOYOTA: AIR/FUEL SENSOR RESPONSE CIRCUIT MALFUNCTION

Description of DTC code P1133

Previously, the Oxygen Sensors were not heated. They did not have the proper fuel adjustment effect in the short term until they reached their optimal operating temperature. On the other hand, today’s heated O2 Sensors reach this temperature in a shorter time, which allows these sensors to be activated almost immediately when the engine is started, thus, emissions are reduced.

When the engine is started, the O2 Sensor detects whether the air-fuel mixture is rich or poor, and proceeds to generate an appropriate voltage, which ranges from 0.1 to 0.9 volts. The intermediate point is 0.45v, which shows that the mixture received by the engine is ideal.

The configuration of fault code P1133 OBDII occurs when the PCM (Powertrain Control Module) detects that the switching cycles between a rich condition and an adjusted execution at a certain time are not enough. Most manufacturers indicate that the problem is in sensor 1, i.e. the sensor upstream of the Catalyst.

Symptoms of fault code P1133

Check Engine lamp illuminated.
The starting of the engine presents difficulties.
Increased fuel consumption.
Large amounts of black smoke are expelled from the exhaust.

Causes of OBD2 P1133

The diagnostic code P1133 OBD2 is set by one or more of the following reasons:

The circuit may have bad wires, connectors, or other components.
One or more Oxygen Sensors may be defective.
The exhaust gas recirculation valve may be blocked.
The system could have exhaust leaks, which create air pollution from the O2 Sensors.
The air entering the engine may not be measured correctly.
The MAF Sensor may be defective.
One of the engine cylinders may be defective.

Possible solutions of the DTC code P1133

The steps to solve the DTC code P1133 OBDII are

To start the diagnosis it is necessary to consult the Technical Service Bulletins.
By using a scanning tool, check if other error codes are stored. If these are related to misfiring or exhaust system problems, you should diagnose them first.
Start the engine and wait until the PCM can use the O2 Sensor voltages to regulate the fuel compensation. Then, open and close the throttle to make changes in oxygen content. If the sensors in the scanner don't have the changes at the right time, check the connectors and cables in the circuit for damage that would cause a short or open circuit. Fix or change any of these that require it.
Disconnect the O2 Sensors from the PCM and perform reference voltage, resistance, continuity, and ground signal checks on the cables related to this sensor. Refer to the service manual for the values required for this circuit and, if inconsistencies are detected, make the appropriate corrections.
Measure the internal resistance of the Oxygen Sensor. If this value is not within the parameters indicated by the manufacturer, you must replace the sensor.