P0302 on Lexus: How to Diagnose & Fix
Cylinder 2 Misfire Detected
4 Lexus models · 5 documented issues · 1 critical · $250-$1,000 repair
P0302 on Lexus by model: symptoms, diagnosis and fix
The direct-injected 2.0L turbo four-cylinder in the IS200t/IS300 accumulates heavy carbon deposits on the intake valves since fuel is not sprayed over the valves to clean them. This leads to rough idle, hesitation under acceleration, and reduced power output typically between 40,000-80,000 miles.
Common Symptoms
- Rough idle or engine vibration
- Hesitation on acceleration from stop
- Reduced power and sluggish throttle response
- Slight misfire feel at low RPM
- Decreased fuel economy
How to Fix
Perform a walnut shell blasting of the intake valves to remove carbon deposits. This requires removing the intake manifold and using specialized media blasting equipment. Plan to repeat every 40,000-60,000 miles. Using a quality catch can helps slow the buildup rate.
Aging valve cover gaskets on the 2JZ-GE commonly harden and leak, allowing oil to seep onto the cylinder head, spark plug tube seals, and exhaust side of the engine. Owners often notice a burnt-oil smell, visible oil around the valve covers, and occasional misfires if oil contaminates ignition components. This is one of the most common age-related engine leaks on the first-gen IS300.
Common Symptoms
- burning oil smell
- oil on valve cover edges
- oil in spark plug wells
- light smoke from engine bay
- misfire under load
- oil spots on driveway
How to Fix
Confirm the leak source by cleaning the engine and inspecting around the valve cover perimeter and spark plug wells. Replace both valve cover gaskets, spark plug tube seals, and related grommets; many owners also replace the PCV valve at the same time to reduce crankcase pressure. If misfires are present, inspect and replace oil-soaked coil boots or plugs.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- 11213-46030 genuine Lexus intake-side valve-cover gasketOEM11213-46030
Supply the intake-side member of the confirmed 2JZ-GE valve-cover reseal Fitment/availability: Live Add to Cart page identifies the intake side, direct-replacement 11213-46030 gasket and includes 2001-2005 IS300 2JZ-GE fitment. Pair with…
- 11214-46011 genuine Lexus exhaust-side valve-cover gasketOEM11214-46011 (replaces 11214-46010)
Supply the exhaust-side member of the confirmed 2JZ-GE valve-cover reseal Fitment/availability: Live Add to Cart page identifies the exhaust side, direct-replacement 11214-46011 gasket, superseding 11214-46010, and includes 2001-2005 IS3…
- 12204-46031 genuine Lexus PCV valveOEM12204-46031
Inspect its grommet and hoses and confirm VIN before ordering.
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Owner tips & cautions
- TipA PCV valve replacement is cheap preventive maintenance when doing this job.
Sources for this issue (1)
The direct-injected 2.0L turbo in the RC200t and RC300 accumulates carbon deposits on the intake valves identically to the IS with the same engine. Without port injection to wash the valves, carbon buildup causes progressive performance degradation starting around 40,000 miles.
Common Symptoms
- Rough idle and engine vibration
- Hesitation on acceleration
- Reduced power output
- Slight misfire feel at low RPM
- Decreased fuel economy
How to Fix
Walnut shell blasting of intake valves every 40,000-60,000 miles. Install an oil catch can to reduce the rate of carbon accumulation. Use top-tier fuel to minimize deposit formation.
Valve springs installed in certain 2007-2008 GS 350 / GS 450h and 2008 GS 460 engines were contaminated during manufacturing with micro foreign objects in the spring wire. The contamination creates a stress riser; over time the spring develops a crack and can break outright. A broken valve spring drops the valve out of control, producing immediate ticking/knocking and rough running, and in the worst case the engine fails and stops suddenly while the car is moving. This affected both the 2GR-FSE V6 (GS 350 / GS 450h) and the 1UR-FSE V8 (GS 460) built in the same period - it is a supplier/material defect, not a design fault of one engine, which is why it spans two different engine families. It does NOT apply to the S160 (1998-2005) cars or to the 2013-2020 L10 generation.
Common Symptoms
- Ticking or tapping noise from the cylinder head
- Rough idle and misfire
- Loss of power
- Engine stalls suddenly while driving
- Check engine light with misfire codes
How to Fix
NHTSA recall 10V309000 (Lexus code ALE). Lexus dealers replace the valve springs with heavy-duty springs, replace the hydraulic lash adjusters/lifters, and renew all gaskets and seals - free of charge with no mileage or time limit on a safety recall. Check the VIN at nhtsa.gov/recalls; the campaign is old enough that most cars were done, but unsold/imported/neglected cars still show it open. If a spring has already broken, the head must come off and valve/piston damage assessed before the recall repair is performed.
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Sources for this issue (3)
The 8AR-FTS 2.0 turbo in the NX 200t and NX 300 is a direct-injected engine, and Lexus direct-injection engines have a long-standing record of fouling intake valves with carbon because fuel never washes across the back of the valve. Lexus partially mitigated this on the 8AR-FTS with D-4S dual injection - a secondary set of port injectors that does spray the intake valves - which is why this engine is markedly better than a direct-injection-only design and why deposits show up later rather than early. It is not eliminated, however: NX owners posting valve inspections past roughly 60,000 miles document meaningful carbon accumulation on the intake valves, and the symptom set is the classic one - rough cold idle, misfires, hesitation and a check engine light. Buyers of higher-mileage AZ10 NX 200t/300 cars should treat this as an inspection item, not an assumption of failure. This is specific to the 8AR-FTS; the NX 300h hybrid's 2AR-FXE and the second-generation engines are not the same case.
Common Symptoms
- Rough or unstable cold idle
- Misfire and check engine light
- Hesitation or stumble under light throttle
- Reduced fuel economy over time
- Slight loss of power and rough running on startup
How to Fix
Diagnosis is a borescope inspection through the intake ports or removal of the intake manifold to view the valves directly - do not chemically treat blind. The definitive fix is walnut shell media blasting of the intake valves with the manifold off, typically $500-$1,000 depending on shop rates. Chemical induction cleaning services are far cheaper but only slow accumulation; they do not remove established hard deposits. Prevention that actually helps on this engine: run full synthetic oil and shorten the oil change interval, since blow-by oil vapor routed through the PCV is the deposit source, and consider an oil catch can. If the check engine light is on, expect misfire codes on the affected cylinders.
Sources for this issue (3)
P0302 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 P0302 mean on a Lexus?
P0302 stands for "Cylinder 2 Misfire Detected." This code means the engine computer has detected a misfire specifically in cylinder 2, meaning that cylinder isn't completing combustion properly on some firing events. The computer watches tiny variations in crankshaft speed to spot when a cylinder fails to fire, and a misfire means the air-fuel mixture isn't igniting correctly — usually from a spark, fuel, or compression problem in that cylinder. You may feel a stumble, rough idle, shaking, loss of power, or a flashing check-engine light, and persistent misfires can damage the catalytic converter. Because it names a single cylinder, the fault is often a component serving just cylinder 2, like its coil, plug, or injector. On Lexus it is documented across 4 models: IS, RC, GS, NX.
What are the most common causes of P0302?
The most common causes of P0302 are: Worn or fouled spark plug (cylinder 2), Failed ignition coil or coil-on-plug (cylinder 2), Clogged or faulty fuel injector (cylinder 2), Vacuum or intake air leak affecting that cylinder, Low compression (worn rings, burnt/bent valve, head gasket), Damaged spark plug wire or boot (if equipped), Carbon-tracked or cracked coil/plug causing spark loss, Faulty PCM/ECM driver (rare). The specific cause varies by vehicle.
How much does it cost to fix P0302 on a Lexus?
Published repair estimates on Lexus range from $250 to $1,000 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 P0302 on a different make?
View P0302 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.