P0302 on Jeep
Cylinder 2 Misfire Detected
P0302 on Jeep vehicles indicates cylinder 2 misfire detected. Au7o has documented this code across 3 Jeep models — most commonly on Grand Cherokee, Liberty, Wrangler. 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 Jeep range from $100 to $4,500, 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 Jeep by Model
Jeep Grand Cherokee(1 issue)
- HEMI Engine Tick/Lifter Noise2011-2021
HEMI-equipped Grand Cherokees can develop the characteristic MDS lifter tick. This ticking noise is most noticeable at idle and during light throttle. While often not immediately harmful, it indicates lifter wear from the MDS cylinder deactivation system.
Jeep Liberty(1 issue)
- 3.7L V6 Exhaust Manifold Crack / Valve Cover Oil Leaks2002-2012
The 3.7L PowerTech V6 engine suffers from two common issues: cracked exhaust manifolds (causing ticking noise and exhaust leak) and valve cover gasket oil leaks. The cast iron exhaust manifolds develop stress cracks due to thermal cycling, with the passenger side being more common. TSB 09-001-10 addressed valve cover oil leaks. Head gasket failures have also been reported on higher-mileage engines.
Jeep Wrangler(2 issues)
- 3.6L Pentastar V6 left cylinder head failure / engine tick (early build)2012-2017
Early 3.6L Pentastar V6 Wranglers (especially 2012 and early-2013 builds) suffered a left (driver-side) cylinder head defect where the head would overheat and damage a valve seat/guide, causing low compression, a persistent ticking/tapping noise (often described as a 'left bank tick'), misfires, rough idle and reduced power. FCA acknowledged the defect and issued extended-warranty coverage (campaign X56) extending the head/related coverage to 10 years / 150,000 miles. A separate, related Pentastar tick on later builds is caused by failed rocker-arm needle bearings or collapsed valve lifters rather than the head casting. A class action was filed over the 3.6L tick. Left unaddressed, valvetrain wear can progress to major top-end engine damage.
- Ignition Coil Rail Failure Causing Misfire on 4.0L2000-2006
The 4.0L coil-rail ignition system used on TJ Wranglers is known to develop internal failures that cause intermittent or persistent misfires. Owners report rough idle, hesitation, flashing check-engine lights, and cylinder-specific misfire codes, often after moisture intrusion, age, or heat exposure. Because the rail serves all cylinders, diagnosis can be less straightforward than on engines with individual plug wires.
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View P0302 across all makes →Frequently Asked Questions
What does P0302 mean on Jeep?▼
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 Jeep specifically, this code is documented across 3 models.
What causes P0302 on Jeep vehicles?▼
Common causes on Jeep: 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 Jeep?▼
Repair costs on Jeep range from $100 to $4,500, depending on the specific model and root cause.
Which Jeep models have P0302 documented?▼
Au7o has documented P0302 on 3 Jeep models: Grand Cherokee, Liberty, Wrangler.