P219B The engine computer has detected that one or more cylinders on bank 2 are running a noticeably different air-fuel mixture from the others

Air-fuel ratio imbalance, bank 2

P219B in short

P219B means the computer has found that one or more bank 2 cylinders are running a different air-fuel mixture from the others. Clogged or leaking injectors are a common cause, especially on some Honda V6s, along with intake leaks and sensor wiring faults. Get it inspected soon; stop if the check engine light flashes.

Each cylinder should get the same mixture. The computer watches the upstream air-fuel sensor signal on each bank, and if it swings in a way that suggests one cylinder is richer or leaner than its neighbours, it sets an imbalance code. P219B is for bank 2, the side without cylinder 1.

Honda calls this an air-fuel ratio variation and lists it with misfire and catalyst codes on 2016-2019 Odyssey, Pilot and Ridgeline. Its later bulletins say debris from the high-pressure fuel pump or injector machining can clog injectors, and owners report dealers replacing all six.

Other makers have different causes. Toyota changed engine computer logic, Mazda added a harness to stop electrical noise on the A/F sensor lines, and Nissan told technicians not to replace the A/F sensor for this code.

Most likely causes

  1. Clogged, worn or leaking fuel injectors on bank 2

    Supported by vehicle data
    Why it ranks here
    Honda bulletins cite injector clogging from debris, and Honda dealers replaced injectors for P219B on Pilots.
    What would change this
    Likelier on a covered Honda V6, or if one cylinder's misfire count or fuel trim stands out.
    How to test the fuel injector

  2. Vacuum or exhaust leak near one cylinder

    Common general cause
    Why it ranks here
    A leak affects one cylinder or the sensor reading more than others; KBB lists vacuum and exhaust leaks.
    What would change this
    Likelier if smoke testing finds a leak at an intake gasket or exhaust joint on bank 2.
    How to test the vacuum hoses and intake leaks

  3. A/F sensor signal noise or wiring fault

    Supported by vehicle data
    Why it ranks here
    Mazda separated the A/F sensor signal lines to cure electrical noise, and KBB lists O2 sensor and wiring faults; Nissan warns not to replace the sensor without diagnosis.
    What would change this
    Likelier on a Mazda CX-9 covered by the bulletin or if the sensor wiring is damaged.
    How to test the oxygen (o2) sensor

  4. Engine computer software

    Supported by vehicle data
    Why it ranks here
    Toyota revised ECM logic for P219B, and Honda's bulletins include a PCM software update.
    What would change this
    Likelier on a model with a software bulletin and no misfire.
    How to test the engine control module (ecm / pcm)

  5. Airflow sensor or fuel supply fault

    Possible — needs testing
    Why it ranks here
    KBB lists the MAF sensor and fuel pump, though these usually affect both banks.
    What would change this
    Likelier if P219A or lean/rich codes for both banks are also stored.
    How to test the mass airflow (maf) sensor

What to test first

Start at step 1. Each result tells you what it means and where to go next.

  1. Read all codes and freeze-frame data, and check for misfire counts by cylinder and catalyst codes such as P0430

    Low riskTool: OBD-II scan tool

  2. Check for intake vacuum leaks and exhaust leaks ahead of the bank 2 upstream sensor, and inspect the sensor wiring

    Use cautionTool: Smoke machine, flashlight

    Warning:Exhaust parts get hot enough to burn; let the engine cool fully before touching sensors or pipes.

  3. Perform an injector balance or flow test on bank 2 following the maker's procedure

    Best left to a shopTool: Bidirectional scan tool, fuel pressure gauge

    Warning:Direct-injection fuel systems run at very high pressure; injector testing and removal must follow the maker's procedure.

Symptoms

  • Check engine light or emissions system warning
  • Reduced fuel economy
  • Rough running or misfire Gets more serious: stop and have it checked.
  • Flashing check engine light Gets more serious: stop and have it checked.

Compare with: Rough idle with the check engine light on

How to fix

  1. Ask a Honda, Toyota, Mazda or Nissan dealer to check your VIN for bulletins, recalls and warranty extensions; Honda extended coverage on some V6 injectors.

  2. Avoid long, hard drives until it's diagnosed, and stop if the check engine light starts flashing.

Parts and cost context

  • Fuel injector:On direct-injection engines injectors are often replaced as a set with new seals. Check for extended warranty coverage first. Labour varies; get a quote.

Labor varies by vehicle and shop; get a quote before you approve a repair.

Compare used part prices on PartPriceGuide

On your vehicle

Honda

  • 2016–2019 · Pilot

    Supported by vehicle data

    Honda bulletins cover catalyst and imbalance codes with injector debris and software; dealers have replaced injectors for P219B. Whether the bulletin is still current is not verified.

  • 2017–2019 · Odyssey

    Supported by vehicle data

    Same Honda V6 bulletins as the Pilot. Whether the bulletin is still current is not verified.

  • A17-036Status unverified

    MIL with P0430 and possibly P030X, P219A or P219B

    2016–2018odyssey, pilot, ridgeline · issued · NHTSA 10162448

    MIL with P0430 (bank 2 catalyst efficiency); P030X misfire, P219A and P219B (air-fuel ratio variation) may also be stored.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • A20-100Status unverified

    PCM software and injector debris; catalyst and imbalance DTCs

    2016pilot · issued · NHTSA 10183520

    PCM software may misread inputs as a deteriorated converter, and debris from the high-pressure pump or injector machining can clog injectors; catalyst and related DTCs may be stored.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • A21-010Status unverified

    PCM software and injector debris; catalyst and imbalance DTCs

    2017–2019odyssey, pilot, ridgeline · issued · NHTSA 10187008

    Same condition as A20-100 for 2017-2019 Odyssey, Pilot and Ridgeline.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Toyota

  • 2012–2013 · Camry

    Supported by vehicle data

    Toyota revised ECM logic to reduce P219A/P219B. Whether the bulletin is still current is not verified.

  • T-SB-0247-12Status unverified

    ECM logic revised for P219A/P219B

    2012–2013camry, avalon, sienna, venza · issued · NHTSA 10053766

    ECM logic was modified to reduce the MIL with P219A or P219B.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Mazda

  • 2011–2013 · CX-9

    Supported by vehicle data

    Engine harness noise on the A/F sensor lines can set P219B. Whether the bulletin is still current is not verified.

  • 01-027-13Status unverified

    P219A/P219B from A/F sensor signal-line noise

    2011–2013cx-9 · issued · NHTSA 10097802

    MIL with P219A and/or P219B from electrical noise in the engine harness; a short cord separates the A/F sensor signal lines.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • P219AThe engine computer has detected that the cylinders on bank 1 are running at noticeably different air-fuel ratios from each other

    Other bank Supported by vehicle data

    P219A is the same imbalance check on bank 1; Toyota, Mazda, Nissan and Honda bulletins cover both.

  • P0430Catalytic converter efficiency below the computer's limit (Bank 2)

    Shares causes Supported by vehicle data

    Honda lists P0430 with P219B on Odyssey, Pilot and Ridgeline V6s, where clogged injectors affect the bank 2 converter reading.

  • P0300Random or multiple-cylinder misfire detected

    Shares causes Supported by vehicle data

    Honda bulletins list misfire codes with P219B when an injector is clogged.

All Fuel trim (air-fuel mixture) codes

P219B questions

Should I replace the air-fuel sensor for P219B?

Not without testing. The sensor is usually reporting a real difference between cylinders. Nissan specifically tells technicians not to replace it for this code, and Honda's repairs focus on injectors and software.

Sources and review

  1. P219B Bank 2 Air-Fuel Ratio Imbalance — Kelley Blue Book
  2. Honda A17-036: MIL with P0430 and possibly P030X/P219A/P219B (Odyssey, Pilot, Ridgeline) — American Honda ,
  3. Honda A21-010: PCM software and injector debris; catalyst and imbalance DTCs (Odyssey, Pilot, Ridgeline) — American Honda ,
  4. Final Regulation Order: 13 CCR §1968.2, Malfunction and Diagnostic System Requirements (OBD II) for 2004 and later passenger cars, light-duty trucks and medium-duty vehicles — California Air Resources Board
  5. 2026 Honda Pilot Owner's Manual: Indicator Coming On/Blinking (Malfunction Indicator Lamp) — American Honda Motor Co.
  6. Honda A20-100: PCM software and injector debris; catalyst and imbalance DTCs (Pilot) — American Honda ,
  7. NHTSA complaint ODI 11270321: 2016 Honda Pilot, Honda dealer found P0430/P219B and recommended replacing all six injectors — NHTSA Office of Defects Investigation
  8. NHTSA complaint ODI 11564228: 2019 Honda Pilot, dealer found P219B and said the fuel injectors needed replacement — NHTSA Office of Defects Investigation
  9. Mazda 01-027-13: P219A/P219B from electrical noise on A/F sensor signal lines (CX-9) — Mazda ,
  10. Nissan NTB19-021: MIL with P219A/P219B; do not replace the A/F sensor (Titan XD VK56D) — Nissan ,
  11. Toyota T-SB-0247-12: ECM logic revised to reduce MIL with P219A/P219B — Toyota ,
Last reviewed
Written by
Saurabh K.
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