P0302 on Porsche
Cylinder 2 Misfire Detected
P0302 on Porsche vehicles indicates cylinder 2 misfire detected. Au7o has documented this code across 3 Porsche models — most commonly on 718 Cayman, 911, Panamera. 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 Porsche range from $600 to $28,000, 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 Porsche by Model
Porsche 718 Cayman(1 issue)
- Direct Injection Intake Valve Carbon Buildup2017-2025
The 718 Cayman turbo flat-four and naturally aspirated flat-six engines use direct injection, which does not wash the intake valves with fuel. Carbon deposits accumulate on the intake valves over time, restricting airflow and causing rough idle, misfires, and power loss. The turbo engines are more prone due to higher intake temperatures.
Porsche 911(1 issue)
- Direct Injection Intake Valve Carbon Buildup2009-2019
The direct injection system on 991 engines does not spray fuel over the intake valves, allowing carbon deposits to accumulate on the valve stems and ports. Over time this restricts airflow, causing rough idle, misfires, and reduced power. The flat-six layout makes walnut blasting more labor-intensive than on inline engines.
Porsche Panamera(2 issues)
- Direct-Injection Intake Valve Carbon Buildup and Misfire2010-2024
Every Panamera engine uses direct fuel injection, so no fuel ever washes across the back of the intake valves. Oil vapour drawn in through the PCV system bakes onto the valve stems and ports and gradually chokes airflow. On the naturally aspirated 3.6 V6 fitted to the base 970 the deposits are the classic case, and the boosted V6s show the same pattern. Symptoms are progressive rather than sudden: rough or lopey idle first, then hesitation and dulled throttle response, then stored misfire codes as the deposits become severe enough to disturb cylinder filling. Owners typically notice it somewhere between roughly 50,000 and 80,000 miles. This is an architectural characteristic of DFI, not a manufacturing defect, and no recall or warranty extension covers it - which is exactly why it catches second and third owners out.
- 4.8L V8 Alusil Cylinder Bore Scoring2010-2016
The 4.8-litre V8 used in the 970 Panamera S, 4S, GTS, Turbo and Turbo S uses Alusil - a silicon-impregnated aluminium block where the bore surface is the block itself, exposed by etching. When that silicon layer breaks down, the piston skirt scores the bore, usually cylinder 2 or cylinder 5 first. The result is climbing oil consumption, a persistent misfire on the affected cylinder, lost compression and eventually a knocking noise. Contributing factors documented by rebuilders are extended oil-change intervals, hard running before the engine reaches temperature, and poor fuel or oil quality. Rebuilders note the failure is far more common on the Cayenne and Macan applications of these Alusil blocks than on the Panamera, so it should be treated as a pre-purchase inspection item rather than an expected event - but when it happens the engine needs to come out, and buyers of high-mileage 4.8 cars need a leak-down and a borescope before signing. This is unrelated to the timing chain and coolant pipe failures on the same engine.
Looking for P0302 on a different make?
View P0302 across all makes →Frequently Asked Questions
What does P0302 mean on Porsche?▼
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 Porsche specifically, this code is documented across 3 models.
What causes P0302 on Porsche vehicles?▼
Common causes on Porsche: 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 Porsche?▼
Repair costs on Porsche range from $600 to $28,000, depending on the specific model and root cause.
Which Porsche models have P0302 documented?▼
Au7o has documented P0302 on 3 Porsche models: 718 Cayman, 911, Panamera.