P0301 on SEAT
Cylinder 1 Misfire Detected
P0301 on SEAT vehicles indicates cylinder 1 misfire detected. Au7o has documented this code across 1 SEAT model — most commonly on Leon. P0301 means the engine computer detected a misfire specifically in cylinder 1 — the spark didn't ignite the fuel properly, or the fuel/air mix didn't burn as it should. The computer detects this by sensing tiny variations in crankshaft speed each time a cylinder fires. A misfire wastes fuel, raises emissions, and can damage the catalytic converter if it's severe or persistent (a flashing check engine light usually warns of active, converter-damaging misfires). Because the code points to one specific cylinder, the cause is usually an ignition, fuel, or compression problem isolated to that cylinder. Typical repair costs on SEAT range from $350 to $700, depending on the specific model and root cause.
Common Causes of P0301
- •Worn or fouled spark plug in cylinder 1
- •Failed ignition coil or coil pack for cylinder 1
- •Faulty or clogged fuel injector for cylinder 1
- •Vacuum or intake air leak affecting that cylinder
- •Bad spark plug wire (on applicable engines)
- •Low compression (worn rings, leaking or burnt valve, head gasket)
- •Carbon buildup on intake valves
- •Wiring or connector fault to the coil or injector
P0301 on SEAT by Model
SEAT Leon(1 issue)
- Leon Mk3 2.0 TSI (EA888 Gen 3) Intake Valve Carbon Buildup2012-2020
Direct-injection EA888 Gen 3 2.0 TSI engines (Leon Cupra, Tiguan, Golf R) accumulate carbon on intake valves because fuel never washes the valves — port injection (which detergent fuels would clean) is absent. Symptoms appear 80,000-130,000 km: rough idle, misfire codes, reduced economy, sometimes failed emissions tests.
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View P0301 across all makes →Frequently Asked Questions
What does P0301 mean on SEAT?▼
P0301 stands for "Cylinder 1 Misfire Detected." P0301 means the engine computer detected a misfire specifically in cylinder 1 — the spark didn't ignite the fuel properly, or the fuel/air mix didn't burn as it should. The computer detects this by sensing tiny variations in crankshaft speed each time a cylinder fires. A misfire wastes fuel, raises emissions, and can damage the catalytic converter if it's severe or persistent (a flashing check engine light usually warns of active, converter-damaging misfires). Because the code points to one specific cylinder, the cause is usually an ignition, fuel, or compression problem isolated to that cylinder. On SEAT specifically, this code is documented across 1 model.
What causes P0301 on SEAT vehicles?▼
Common causes on SEAT: Worn or fouled spark plug in cylinder 1, Failed ignition coil or coil pack for cylinder 1, Faulty or clogged fuel injector for cylinder 1, Vacuum or intake air leak affecting that cylinder, Bad spark plug wire (on applicable engines). Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0301 on a SEAT?▼
Repair costs on SEAT range from $350 to $700, depending on the specific model and root cause.
Which SEAT models have P0301 documented?▼
Au7o has documented P0301 on 1 SEAT model: Leon.