The Lemon IndexThe downstream O2 sensor isn't sending a usable signal.
Drive on, get it checked. You can usually keep driving. Have the code read at your next service or within a few weeks.
Failed O2 sensor. Then: open wiring.
Owners named P0140 in 7 complaints to the U.S. government, most often on the Infiniti.
The details
What P0140 means
The downstream O2 sensor isn't sending a usable signal.
Can I drive with P0140?
Drive on, get it checked. You can usually keep driving. Have the code read at your next service or within a few weeks.
43% of the owner complaints that name P0140 also say the car rattles or knocks. A complaint can describe more than one problem, so this doesn't prove the code caused it.
Common causes of P0140
- Failed O2 sensor
- Open wiring
A shop should confirm the cause with a scan and tests before replacing parts.
What owners describe
- Rattles or knocks: 43% of complaints
- Warning lights and electrical faults: 43% of complaints
- Loses power or goes into limp mode: 43% of complaints
- Stalls or shuts off: 29% of complaints
Share of complaints naming the code whose text also mentions each problem.
Related codes
P0141 P0138 P0137 P0136 P0135 P0133 P0131 P0128
Quick answers
What does P0140 mean?
O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 2). The downstream O2 sensor isn't sending a usable signal.
Can I drive with P0140?
Drive on, get it checked. You can usually keep driving. Have the code read at your next service or within a few weeks.
What causes P0140?
Failed O2 sensor; Open wiring.
Counts: NHTSA owner complaints whose text names P0140. A complaint is an owner's report, not a diagnosis. Meanings: the standard SAE J2012 definitions in our own words; manufacturer codes only where verified for that make. General information, not repair advice for your car.