Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC P0133
DTC P0133 : A/F Sensor (Sensor 1) Malfunction/Slow Response
NOTE:
- Before you troubleshoot, review the general troubleshooting information .
- If DTC P0139 is stored at the same time as DTC P0133, troubleshoot DTC P0139 first, then recheck for DTC P0133.
| DTC Description | Confirmed DTC | Pending DTC | Freeze Frame |
|---|---|---|---|
| P0133 A/F Sensor (Sensor 1) Malfunction/Slow Response |
DTC (PGM-FI)
- Problem verification
-1. Turn the vehicle to the ON mode.
-2. Clear the DTC with the HDS.
-3. Start the engine. Hold the engine speed at 3, 000 rpm without load (CVT in P or N, M/T in neutral) until the radiator fan comes on, then let it idle.
-4. Test-drive under these conditions:
- Engine coolant temperature (ECT SENSOR 1) above 158 deg. F (70 deg. C)
- CVT in D, M/T in 3rd or 4th
- Engine speed between 1, 400-3, 300 rpm
- Drive the vehicle at 25 mph (40 km/h) or less for 5 minutes, then drive at a steady speed of 32 mph (52 km/h) or more
Signal Current conditions Values Unit ECT SENSOR 1 ENGINE SPEED VEHICLE SPEED -5. Monitor the OBD STATUS for DTC P0133 in the DTCs MENU with the HDS.
DTC Description OBD STATUS P0133 A/F Sensor (Sensor 1) Malfunction/Slow Response Does the HDS indicate FAILED?
YES
Replace the A/F sensor (Sensor 1) .
NO
If the HDS indicates PASSED, intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the freeze data/on-board snapshot . If the HDS indicates EXECUTING, keep driving until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 1-3 on this step and recheck.
NO RELATED
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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.