All codes › P0133
P0133: O2 Sensor Circuit Slow Response (Bank 1 Sensor 1)
What it means
The upstream O2 sensor on bank 1 (before the catalytic converter), which the computer uses to adjust fuel mixture is switching between rich and lean too slowly. It's aging.
Severity: Low Classic aging-sensor code; economy slowly drops.
Common causes
- Aged or contaminated O2 sensor
- Exhaust leak
- Oil or coolant contamination
- Wiring resistance
Most common causes first. Exact causes vary by make, model and engine.
Can I fix it myself?
Often DIY. Upstream sensors past ~100k miles are usually just worn out.
Repair cost
SEEDED ESTIMATE Roughly $70–$330
Most likely repair: oxygen sensor. Diagnosis fees, taxes and other causes are not included.
| Line | Low | High | Basis |
|---|---|---|---|
| Oxygen sensor | $36 | $168 | Typical listed retail range, source |
| Labor 0.3–1 hr | $30 | $160 | $100–$160/hr, shop survey |
⚠️ This is an editorial placeholder range for this type of repair. It is not based on real invoices or licensed pricing data yet. Real ranges will appear here once enough reader invoices for P0133 are verified.
Verified reader invoices for P0133: 0. Share your repair bill to help build real costs.
Tools that can read P0133
- ScanFixAI: Pro $29.99/mo or $249.99/yr
- OBDAI: Annual PRO bundle $299
- BlueDriver Pro Next-Gen: $119.95 list ($99.95 sale seen)
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