P0305 on Toyota: How to Diagnose & Fix
Cylinder 5 Misfire Detected
2 Toyota models · 2 documented issues · 2 critical · $1,800-$4,000 repair
P0305 on Toyota by model: symptoms, diagnosis and fix
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.
Common Symptoms
- Engine misfires
- Check engine light
- Rough idle or running
- Loss of power
- Engine stall while driving
How to Fix
This is covered under recall 22V-879 (Toyota) / WRJ-23 (Subaru). Contact Toyota dealer to check VIN eligibility. The repair involves replacing all 16 intake and exhaust valve springs at no cost. Do not ignore this recall - a fractured valve spring can cause catastrophic engine damage.
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Sources for this issue (1)
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.
Common Symptoms
- slow coolant loss with no obvious front-engine leak
- sweet coolant smell
- coolant residue on rear of engine
- overheating
- rough running on cold start
- misfire
How to Fix
Pressure-test the cooling system, inspect for coolant residue at the rear of the heads, and check for combustion-gas intrusion if overheating or misfires are present. Repair typically involves head gasket replacement, machine-shop inspection of the heads, and replacement of related seals, head bolts, water pump, and timing components as needed. Continuing to drive with low coolant can lead to severe engine damage.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Fel-Pro HS 26330 PT complete cylinder-head gasket set
complete gasket-set branch after a head-gasket failure is confirmed and both heads are inspected Fitment/availability: 2003-2009 Toyota 4Runner 4.0L V6 1GR-FE according to retailer; review is for 2003-2006 and head bolts are explicitly n…
- Fel-Pro ES 72249 cylinder-head bolt set
new torque-to-yield head bolts required with the approved gasket-set repair Fitment/availability: 2003-2020 Toyota 4Runner 4.0L V6 listing; confirm 1GR-FE VIN and required set quantity with the service procedure before purchase Fitment/a…
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Sources for this issue (3)
P0305 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0305 mean on a 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 it is documented across 2 models: GR86, 4Runner.
What are the most common causes of P0305?
The most common causes of P0305 are: 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. The specific cause varies by vehicle.
How much does it cost to fix P0305 on a Toyota?
Published repair estimates on Toyota range from $1,800 to $4,000 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0305 on a different make?
View P0305 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.