The other day, my Dodge had a PO133 code (slow response O2 sensor bank 1 sensor 1) after an alternator replacement. I suspect a loose battery cable, potentially overlooked during the repair, might be the culprit. Before replacing the sensor, I want to reset the OBDII monitors and see if the code returns. Disconnecting the battery for five hours didn’t clear it. Will this OBDII drive cycle reset the monitors and clear the code if the sensor is functioning correctly?
Dodge OBDII Monitor Reset Drive Cycle
This drive cycle starts with a cold start (coolant below 122°F, coolant and air temperature sensors within 11°F of each other). Important: Don’t turn the ignition on before the cold start; otherwise, the heated oxygen sensor diagnostic might not run.
Phase 1: Idle and Initial Checks (2.5 minutes)
Immediately after starting the engine, idle in drive for two and a half minutes with the A/C and rear defrost on. This phase checks the oxygen sensor heater circuits, air pump, and EVAP purge system.
Phase 2: Acceleration and System Checks (3 minutes)
Turn off the A/C and rear defrost. Accelerate to 55 mph at half throttle. This checks for ignition misfire, fuel trim, and canister purge function.
Phase 3: Steady State Cruise and Monitoring (3 minutes)
Maintain a constant 55 mph for three minutes. This allows the OBDII system to monitor the EGR system, air pump, O2 sensors, and canister purge.
Phase 4: Deceleration and EGR/Purge Check
Decelerate to 20 mph without using the brakes or clutch. This phase focuses on evaluating the EGR and purge functions.
Phase 5: Second Acceleration and System Check
Accelerate back to 55-60 mph at half throttle. This repeats the misfire, fuel trim, and purge checks.
Phase 6: Extended Cruise and Comprehensive Monitoring (5 minutes)
Hold a steady speed of 55-60 mph for five minutes. This extended period monitors catalytic converter efficiency, misfire, EGR, fuel trim, oxygen sensors, and purge functions.
Phase 7: Final Deceleration and EGR/Purge Check
Coast down to a complete stop without braking. This final check focuses on the EGR and canister purge system.
By completing this specific drive cycle, the Dodge OBDII monitors should reset, allowing you to determine if the PO133 code returns. If the code reappears, it indicates a potential issue with the oxygen sensor. If not, the loose battery cable might have been the cause.
