P0266 Cylinder 2 is not contributing as much power as the other cylinders

Cylinder 2 contribution/balance fault

Severity not verified — if the car runs badly, have it inspected

No source here rates the urgency of a cylinder balance fault, so the class is not verified. The cause can be a dirty injector or an engine mechanical problem, so the effect ranges from nothing noticeable to a rough, weak engine.

It gets more serious if:

  • Inspect soon: Inspect soon if the engine misfires, runs rough, loses power or stalls.

Source: how we rate severity

P0266 in short

P0266 means the engine computer found cylinder 2 contributing less than the others, judged from crankshaft speed. TroubleCodes.net lists dirty injectors as the most common cause, then mechanical faults such as burnt valves, worn rings or a leaking head gasket.

The computer compares how much each cylinder speeds the crankshaft. P0266 is set when cylinder 2 falls short of the rest.

TroubleCodes.net says a dirty fuel injector is the most common reason. Mechanical faults such as burnt valves, worn piston rings or a leaking head gasket can also cut a cylinder's output.

Most likely causes

These are general causes for this code across vehicles. None is specific to one make or model.

  1. Dirty or clogged injector on cylinder 2

    Common general cause
    Why it ranks here
    TroubleCodes.net names dirty injectors as the most common cause.
    What would change this
    Rises if a waveform or sound comparison shows injector 2 differs from its neighbours. Falls if it matches.
    How to test the fuel injector

  2. Engine mechanical fault on that cylinder (valves, rings, head gasket)

    Possible — needs testing
    Why it ranks here
    Listed by TroubleCodes.net as the other main group of causes.
    What would change this
    Rises if compression or leakdown differs noticeably from other cylinders. Falls if they match.

What to test first

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

  1. With the engine off, check the cylinder 2 injector connector for corrosion or water.

    Low risk

  2. Have a compression and leakdown test done and compare cylinders; readings should not differ by more than about 10%.

    Best left to a shopTool: compression gauge, leakdown tester

    Warning:Testing involves removing spark plugs or glow plugs and cranking the engine with the fuel and ignition disabled; hot parts and a spinning engine are nearby. A shop should do this.

Symptoms

  • Check engine light
  • Rough idle or misfire
  • Reduced power and fuel economy

Compare with: Car shaking with the check engine light on

How to fix

Parts and cost context

  • Fuel injector:Test the injector and wiring before replacing; labor 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

Kia

  • 2014–2015 · Optima

    Supported by vehicle data

    NHTSA bulletin summary for this model: covers fuel injector replacement on 2.4 GDI engines with P0266 among the codes. Whether it is still current is not verified.

  • 2014–2015 · Sorento

    Supported by vehicle data

    NHTSA bulletin summary for this model: covers fuel injector replacement on 2.4 GDI engines with P0266 among the codes. Whether it is still current is not verified.

  • 2014–2015 · Sportage

    Supported by vehicle data

    NHTSA bulletin summary for this model: covers fuel injector replacement on 2.4 GDI engines with P0266 among the codes. Whether it is still current is not verified.

  • TSBENG149Status unverified

    2.4 GDI MIL with P0263, P0266, P0269 or P0272: fuel injector replacement

    2014–2015optima, sorento, sportage · issued · NHTSA 10089301

    Provides information about replacing the fuel injectors on some 2014-2015 Sorento, Optima and Sportage with the 2.4 GDI engine and the MIL on with P0263, P0266, P0269 or P0272. The repair details are not in the summary. Only the NHTSA flat-file summary was read, not the bulletin itself.

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

Volkswagen

  • 2013–2014 · Beetle

    Supported by vehicle data

    NHTSA bulletin summaries for this model: covers cylinder contribution/balance faults including P0266 stored in ECM fault memory. Whether it is still current is not verified.

  • 2010–2014 · Golf

    Supported by vehicle data

    NHTSA bulletin summaries for this model: covers cylinder contribution/balance faults including P0266 stored in ECM fault memory. Whether it is still current is not verified.

  • 2009–2014 · Jetta

    Supported by vehicle data

    NHTSA bulletin summaries for this model: covers cylinder contribution/balance faults including P0266 stored in ECM fault memory. Whether it is still current is not verified.

  • TB011409Status unverified

    Update programming for cylinder contribution faults with P0266 among codes

    2009–2014beetle, golf, jetta, jetta-sportwagen · issued · NHTSA 10241312

    MIL on with cylinder contribution/balance faults stored in ECM fault memory, listed as P0263, P0266, P0269 and/or P0272. Only the NHTSA flat-file summary was read, not the bulletin itself.

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

  • TB011422Status unverified

    Update programming for cylinder contribution faults with P0266 among codes

    2009–2014beetle, golf, jetta, jetta-sportwagen · issued · NHTSA 10241325

    MIL on with cylinder contribution/balance faults stored in ECM fault memory, listed as P0263, P0266, P0269 and/or P0272. Only the NHTSA flat-file summary was read, not the bulletin itself.

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

  • TB011419Status unverified

    Update programming for cylinder contribution faults with P0266 among codes

    2009–2014beetle, jetta, jetta-sportwagen · issued · NHTSA 10241322

    MIL on with cylinder contribution/balance faults stored in ECM fault memory, listed as P0263, P0266, P0269 and/or P0272. Only the NHTSA flat-file summary was read, not the bulletin itself.

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

  • TB011418Status unverified

    Update programming for cylinder contribution faults with P0266 among codes

    2009–2010touareg · issued · NHTSA 10241321

    MIL on with cylinder contribution/balance faults stored in ECM fault memory, listed as P0263, P0266, P0269 and/or P0272 (and P0275/P0278). Only the NHTSA flat-file summary was read, not the bulletin itself.

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

  • TB011414Status unverified

    Update programming for cylinder contribution faults with P0266 among codes

    2009–2014beetle, jetta, jetta-sportwagen · issued · NHTSA 10241317

    MIL on with cylinder contribution/balance faults stored in ECM fault memory, listed as P0263, P0266, P0269 and/or P0272. Only the NHTSA flat-file summary was read, not the bulletin itself.

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

  • TB011311Status unverified

    Update programming for cylinder contribution faults with P0266 among codes

    2011–2012touareg · issued · NHTSA 10241283

    MIL on with cylinder contribution/balance faults stored in ECM fault memory, listed as P0263, P0266, P0269 and/or P0272 (and P0275/P0278). Only the NHTSA flat-file summary was read, not the bulletin itself.

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

No curated relationships for P0266 yet.

All Fuel pump and injectors codes

Sources and review

  1. P0266 - Cylinder 2 Contribution/Balance Fault — TroubleCodes.net
  2. P0266: NHTSA bulletin 10089301 (2.4 GDI MIL with P0263, P0266, P0269 or P0272: fuel injector replacement) — Manufacturer communication via NHTSA flat file
  3. P0266: NHTSA bulletin 10241312 (Update programming for cylinder contribution faults with P0266 among codes) — Manufacturer communication via NHTSA flat file
  4. P0266: NHTSA bulletin 10241325 (Update programming for cylinder contribution faults with P0266 among codes) — Manufacturer communication via NHTSA flat file
  5. P0266: NHTSA bulletin 10241322 (Update programming for cylinder contribution faults with P0266 among codes) — Manufacturer communication via NHTSA flat file
  6. P0266: NHTSA bulletin 10241317 (Update programming for cylinder contribution faults with P0266 among codes) — Manufacturer communication via NHTSA flat file
  7. On-Board Diagnostic Trouble Codes (generic code title list) — Delaware Division of Motor Vehicles
Last reviewed
Written by
Saurabh K.
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