P015D

O2 Sensor Delayed Response - Lean to Rich Bank 2 Sensor 1

Q: Is it safe to drive with P015D?

Generally yes — the engine still runs, but the slow sensor can slightly upset the mixture and hurt economy. Fix it before an emissions test or if idle gets rough.

Q: Can I just clear P015D?

It will return after a few drive cycles unless the sluggish sensor, its wiring, or an underlying mixture problem is corrected.

Fuel & air metering (O2 sensor) Generic OBD-II Medium

What it means

P015D means the upstream oxygen sensor on bank 2 (sensor 1) takes too long to react when the mixture swings from lean to rich. This front sensor guides the computer's fuel control, so a delayed signal can slightly upset fueling and economy. It's most often an aging sensor, but wiring faults, exhaust or intake leaks, and fuel-delivery problems can trigger the same code.

Medium

Can I keep driving? Usually safe to drive — you may notice slightly worse economy or a mild surge, but it's mainly a fuel-mixture and emissions concern.

Real-world scan data

Seen in

scans in the past year

Found in

<0.1%

of scans

<0.1%

of scans that found faults

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Check-engine light on
Rough idle or mild surging
Increased fuel consumption
Failed emissions test

Common causes

Most likely first

Aged or contaminated upstream oxygen sensor (bank 2, sensor 1)Likely
Sensor wiring open, shorted, or corrodedCommon
Poor electrical connection at the sensorCommon
Intake air or exhaust leaks skewing the readingLess often
Fuel-delivery issues (pressure or injectors) upsetting the mixtureLess often

How to diagnose & fix

Work through it in order

Read freeze-frame data and check the fuel-trim values for bank 2.
Inspect the sensor wiring and connector for damage or corrosion.
Check for intake and exhaust leaks near the sensor.
Verify fuel pressure and injector operation if the trims are skewed.
Replace the upstream oxygen sensor if it responds slowly with everything else good.

FAQ

Quick answers

Is it safe to drive with P015D?+

Generally yes — the engine still runs, but the slow sensor can slightly upset the mixture and hurt economy. Fix it before an emissions test or if idle gets rough.

Can I just clear P015D?+

It will return after a few drive cycles unless the sluggish sensor, its wiring, or an underlying mixture problem is corrected.

Read & clear P015D yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX