P014B code meaning
O2 Sensor Delayed Response - Lean to Rich Bank 2 Sensor 2
Powertrain system Generic code P01xx codes Check engine light
What P014B means
The downstream oxygen sensor (sensor 2, after the catalytic converter) is used for fine mixture trim and to monitor the converter. 'Delayed response' means the sensor starts reacting too late, or does not reach the target level at all, after the mixture has changed. This code covers the lean-to-rich direction, tested when fuel returns or the control module briefly enriches the mixture. Bank 2 only exists on V and boxer engines. GM checks whether the signal rises above 350 mV before about 250 g of air have passed after the forced change; failing needs two trips. GM's 2025 field investigation on Corvettes listed it together with P013E, P013F and P014A. CARB requires separate detection of slow and delayed faults in each direction (phased in from 2009 for downstream and 2011 for upstream sensors).
P014B at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyEasy, DIY possible
- Typical labor0.5 to 1.5 hours
- Clears after repairAfter a drive cycle
Symptoms of P014B
- Check engine light on
- Usually no noticeable change in driving
- Catalyst monitor may stay incomplete (inspection readiness missing)
- With a converter cause, P0420/P0430 may follow
Common causes of P014B
- Most likelyDownstream oxygen sensor aged or contaminated (soot, oil, silicone, coolant)
- PossibleExhaust leak between manifold/turbo and the sensor
- PossibleConverter faulty or non-original with different oxygen storage
- Less likelyControl module software too sensitive (update available)
- Less likelySensor connector or wiring with contact resistance
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Oxygen sensor bank2 sensor2Exhaust systemCatalytic converter
What each part of P014B means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 1 | Area: fuel and air metering. |
| 4B | The exact fault in that area. |
What to do next
- Note P014B and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P014B
What does P014B mean?
P014B means "O2 Sensor Delayed Response - Lean to Rich Bank 2 Sensor 2". The downstream oxygen sensor (sensor 2, after the catalytic converter) is used for fine mixture trim and to monitor the converter. It is a generic code, so it means the same on every make.
Is it safe to drive with P014B?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P014B fail an emissions test?
Yes, it can. P014B is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P014B to fix?
Difficulty: easy. A typical repair takes 0.5 to 1.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P014B clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.