2000 Dodge and Ram Intrepid R/TFACTORY OEM SERVICE PROCEDURE

DTC P0133: 1/1 O2 Sensor Slow Response: Testing

NOTE: 1/1 HO2S may also be referred to as an upstream oxygen sensor. 1/1 HO2S is located in outlet flange of right exhaust manifold.
  1. Using scan tool, read DTCs. If GLOBAL GOOD TRIP counter is displayed and displayed count is "0", go to next step. If GLOBAL GOOD TRIP counter is not displayed or displayed count is not "0", go to step  6.
  2. Start engine and allow it to idle. Check exhaust system for leaks between engine and 1/1 HO2S. Repair exhaust system leaks as necessary. If exhaust system is okay, go to next step.
  3. Turn ignition off. Using voltmeter, backprobe Black/Orange wire between 1/1 HO2S harness connector and terminal No. 27 at PCM C1 harness connector. See Figure. Start engine and allow it to idle. Ensure coolant temperature is at normal operating temperature. Note voltage reading. If voltage drop is less than .1 volt, go to next step. If voltage drop is .1 volt or more, repair poor connection causing high resistance on 1/1 HO2S ground circuit (Black/Orange wire) between 1/1 HO2S and PCM.
  4. Turn engine off. Using a voltmeter, backprobe Black/Dark Green wire between 1/1 HO2S harness connector and terminal No. 30 at PCM C1 harness connector. Start engine and allow it to idle. Ensure coolant temperature is at normal operating temperature. Note voltage reading. If voltage drop is less than .1 volt, go to next step. If voltage drop is .1 volt or more, repair poor connection causing high resistance on 1/1 HO2S signal circuit (Black/Dark Green wire) between 1/1 HO2S and PCM.
  5. At this time, 1/1 HO2S is assumed to be defective. Replace 1/1 HO2S.
  6. Turn ignition off. Visually inspect related connectors and wiring harness for damage. Repair connectors and wiring harness as necessary. If connectors and wiring harness are okay, reconnect all connectors. Start engine. Wiggle 1/1 HO2S connector and wiring harness while monitoring scan tool display. If GOOD TRIP counter display count changes to "0", repair connector or wiring harness where wiggling caused display to change. If GOOD TRIP counter display count does not change to "0", no problem is indicated at this time. Check for any related technical service bulletins that may apply.
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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