P0302 on Pontiac
Cylinder 2 Misfire Detected
P0302 on Pontiac vehicles indicates cylinder 2 misfire detected. Au7o has documented this code across 1 Pontiac model — most commonly on Sunfire. 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 Pontiac range from $1,000 to $2,500, 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 Pontiac by Model
Pontiac Sunfire(1 issue)
- Sunfire 2.2L Ecotec (L61) Head Gasket / Head Crack2002-2005
The first-generation 2.2L Ecotec L61 in 2002-2005 Sunfire (and Cobalt, Cavalier, Saturn Ion) is prone to head gasket failure and cylinder head cracking — particularly if overheated once. Aluminum head warps easily. Often presents as bubbles in coolant reservoir, white smoke, and overheating.
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View P0302 across all makes →Frequently Asked Questions
What does P0302 mean on Pontiac?▼
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 Pontiac specifically, this code is documented across 1 model.
What causes P0302 on Pontiac vehicles?▼
Common causes on Pontiac: 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 Pontiac?▼
Repair costs on Pontiac range from $1,000 to $2,500, depending on the specific model and root cause.
Which Pontiac models have P0302 documented?▼
Au7o has documented P0302 on 1 Pontiac model: Sunfire.