All codes › P0140
P0140: O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 2)
What it means
The downstream O2 sensor on bank 1 (after the catalytic converter), which monitors converter efficiency shows no activity.
Severity: Low Emissions monitoring disabled.
Common causes
- Dead sensor
- Open circuit
- Unplugged connector
- Heater failure
Most common causes first. Exact causes vary by make, model and engine.
Can I fix it myself?
Often DIY. Often an unplugged connector after exhaust work.
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 P0140 are verified.
Verified reader invoices for P0140: 0. Share your repair bill to help build real costs.
Tools that can read P0140
- 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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