P0302 on Alfa Romeo
Cylinder 2 Misfire Detected
P0302 on Alfa Romeo vehicles indicates cylinder 2 misfire detected. Au7o has documented this code across 1 Alfa Romeo model — most commonly on Stelvio. 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. Typical repair costs on Alfa Romeo range from $500 to $1,200, depending on the specific model and root cause.
Common Causes of P0302
- •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)
P0302 on Alfa Romeo by Model
Alfa Romeo Stelvio(1 issue)
- 2.0L Turbo Intake Valve Carbon Buildup Causing Cold-Start Misfire2018-2026
The 2.0L GME turbo four is direct injected, so no fuel washes over the back of the intake valves. Crankcase vapour routed through the PCV system bakes onto the valve heads and forms hard carbon deposits that disrupt airflow and seal quality. What makes the Stelvio case notable is how early it appears: Stelvio and Giulia forum members report being sent for walnut blasting at Alfa's direction at roughly 6,000-6,500 miles because of cold-start misfires, an order of magnitude sooner than the 75,000-125,000 mile window typical of other direct-injection engines. Symptoms are worst on a cold start and often clear once the engine warms, which is why the condition is frequently dismissed on a test drive. This is a 2.0L issue and should not be merged with the 2.9L V6 Quadrifoglio's separate intake-side story.
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What does P0302 mean on Alfa Romeo?▼
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 Alfa Romeo specifically, this code is documented across 1 model.
What causes P0302 on Alfa Romeo vehicles?▼
Common causes on Alfa Romeo: 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). Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0302 on a Alfa Romeo?▼
Repair costs on Alfa Romeo range from $500 to $1,200, depending on the specific model and root cause.
Which Alfa Romeo models have P0302 documented?▼
Au7o has documented P0302 on 1 Alfa Romeo model: Stelvio.