P0133 — 02 Sensor Circuit Slow Response (Bank 1 Sensor 1)
Category: Powertrain Severity: Medium
Updated:
DTC code P0133 means: 02 Sensor Circuit Slow Response (Bank 1 Sensor 1). It falls under the "Powertrain" category, with an estimated severity of Medium. Common causes include faulty oxygen (O2) sensor (Bank 1 Sensor 1), wiring or connector damage/corrosion and exhaust leak near the sensor; it's worth confirming the diagnosis before replacing parts.
Possible causes
- Faulty oxygen (O2) sensor (Bank 1 Sensor 1)
- Wiring or connector damage/corrosion
- Exhaust leak near the sensor
- Blown fuse (if heater-related)
Symptoms
- Check engine light on
- Increased fuel consumption
- Rough idle in some cases
- Possible failed emissions test
How to diagnose it step by step
- Watch the sensor switching rate when warm.
- Look for exhaust and vacuum leaks.
- Check the sensor heater.
- Replace the sensor if it responds slowly.
How to fix it
Inspect the wiring and connector of the Bank 1 Sensor 1 oxygen sensor for damage or corrosion, and check for exhaust leaks nearby. If both are fine, the sensor itself is most likely faulty and should be replaced — O2 sensors wear out over time and don't have a simple repair.
Estimated repair cost
$100–300.
Frequently asked questions
What does DTC code P0133 mean?
02 Sensor Circuit Slow Response (Bank 1 Sensor 1).
Is code P0133 serious?
Severity Medium. Not urgent, but worth diagnosing to avoid bigger damage.
Can I keep driving with code P0133?
Yes, it is safe to drive.
Related codes
P0132 P0134 P0131 P0135 P0130 P0136 P0137 P0138 P0139 P0128
Refine by car make
- Audi P0133: Mass air flow (MAF) sensor or leak.
- BMW P0133: Upstream oxygen sensor.
- Citroën P0133: MAF/MAP sensor or leak.
- Dacia P0133: MAF/MAP sensor.
- Fiat P0133: MAF/MAP sensor.
- Ford P0133: Upstream O2 sensor with slow response.
- Honda P0133: MAF/MAP sensor.
- Hyundai P0133: MAF sensor.
- Kia P0133: MAF sensor.
- Mazda P0133: MAF sensor.
- Mercedes-Benz P0133: MAF sensor or intake leak.
- Nissan P0133: MAF sensor.
- Opel P0133: MAF sensor or leak.
- Peugeot P0133: MAF/MAP sensor or leak.
- Renault P0133: MAF/MAP sensor or leak.
- Toyota P0133: Upstream O2 sensor.
- Volkswagen P0133: O2 sensor or exhaust leak.
- Volvo P0133: MAF sensor.
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