Known Issues/P0305/Toyota

P0305 on Toyota

Cylinder 5 Misfire Detected

Moderate2 Toyota models affected$1,800-$4,000 typical repairSystem: Engine
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P0305 on Toyota vehicles indicates cylinder 5 misfire detected. Au7o has documented this code across 2 Toyota models — most commonly on 4Runner, GR86. This code means the engine control module detected a misfire on cylinder number 5, meaning that cylinder is not burning its air-fuel mixture properly on some combustion cycles. The computer senses misfires by watching for tiny fluctuations in crankshaft speed each time a cylinder fails to fire correctly. A misfire wastes fuel, can make the engine run rough or shake, and dumps unburned fuel into the exhaust, which can overheat and damage the catalytic converter. It generally points to a problem with spark, fuel delivery, or compression specifically affecting cylinder 5. Typical repair costs on Toyota range from $1,800 to $4,000, depending on the specific model and root cause.

Common Causes of P0305

  • •Worn or fouled spark plug on cylinder 5
  • •Failed ignition coil or coil pack for cylinder 5
  • •Faulty or clogged fuel injector on cylinder 5
  • •Vacuum or intake air leak affecting that cylinder
  • •Bad spark plug wire or boot (on applicable engines)
  • •Low compression from worn rings, valves, or head gasket
  • •Carbon buildup or sticking valve on cylinder 5
  • •Lean or rich fuel condition affecting the cylinder

P0305 on Toyota by Model

Toyota 4Runner(1 issue)

  • 1GR-FE V6 Head Gasket Failure with External Coolant Leak at Rear of Cylinder Head2003-2006

    Early 4th-generation 4Runners with the 4.0L 1GR-FE V6 are known for head gasket failures, often presenting as an external coolant leak near the rear of the passenger-side cylinder head. Owners report gradual coolant loss, sweet smell, overheating risk, and misfires if the leak worsens. The issue is widely discussed in owner communities and repair databases, especially on 2003-2006 trucks.

Toyota GR86(1 issue)

  • Valve Spring Recall - Engine Stall Risk2022-2023

    Toyota/Subaru recalled early 2022-2023 GR86 and BRZ models for improperly manufactured valve springs in the FA24 engine. Defective springs can fracture, causing engine misfires, rough running, and potential engine stalling while driving. Recall 22V-879.

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Frequently Asked Questions

What does P0305 mean on Toyota?▼

P0305 stands for "Cylinder 5 Misfire Detected." This code means the engine control module detected a misfire on cylinder number 5, meaning that cylinder is not burning its air-fuel mixture properly on some combustion cycles. The computer senses misfires by watching for tiny fluctuations in crankshaft speed each time a cylinder fails to fire correctly. A misfire wastes fuel, can make the engine run rough or shake, and dumps unburned fuel into the exhaust, which can overheat and damage the catalytic converter. It generally points to a problem with spark, fuel delivery, or compression specifically affecting cylinder 5. On Toyota specifically, this code is documented across 2 models.

What causes P0305 on Toyota vehicles?▼

Common causes on Toyota: Worn or fouled spark plug on cylinder 5, Failed ignition coil or coil pack for cylinder 5, Faulty or clogged fuel injector on cylinder 5, Vacuum or intake air leak affecting that cylinder, Bad spark plug wire or boot (on applicable engines). Specific causes vary by model and year — see the per-model sections below.

How much does it cost to fix P0305 on a Toyota?▼

Repair costs on Toyota range from $1,800 to $4,000, depending on the specific model and root cause.

Which Toyota models have P0305 documented?▼

Au7o has documented P0305 on 2 Toyota models: 4Runner, GR86.

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