P1133

Wiring Diagram:

After achieving closed loop fuel control, a commanded air fuel ratio of 14.7:1, RPM between 1500 and 3200 and air flow between 5 and 20 grams per second the PCM will continuously monitor the front oxygen sensor signal for 100 seconds. During this time the PCM counts the number of rich to lean and lean to rich switches. To be considered a switch the voltage must go below 300 mv and above 600 mv. The PCM also keeps track of the time it takes to make the switch. The number of switches along with the time to achieve these switches are used to calculate the average response time to perform each switch. Also this information is used to calculate if the proper ratio of the switches is correct. The three diagnostic trouble codes listed below are used to identify different types of faults that can occur with oxygen sensors.

DTC PARAMETERS

P0133 - O2 Response Too Slow - This DTC is set if the average response time of the switches from the sensor is too slow after the 100 second test is performed. If the LEAN TO RICH time is less than 94 ms or the RICH TO LEAN time is less than 125 ms this code will set.

P1133 - Too Few Rich To Lean and Lean To Rich Switches - If less than 10 switches take place during the test this code will set.

P1134 - Rich To Lean or Lean To Rich Ratio Error - If the transition ratio of the sensor is greater than 2.8 or less than 0.6 this DTC will set.

DIAGNOSTIC AIDS

Repair Procedure

1. The oxygen sensor wiring and connections should be checked if any of these DTCs are set because corrosion or loose connections could cause these DTCs to set.

2. The most likely cause of setting any of these DTCs is contamination. This contamination could be caused by fuel, improper use of RTV sealant, engine oil, or coolant contamination.

3. The source of contamination should be identified and corrected before replacing the sensor.