P0302 Code: Jeep Cherokee (2019-2023) - Causes, Symptoms & Fixes

Comprehensive diagnostic guide for P0302 on 2019-2023 Jeep Cherokee

Important data note

• This guide is built around the NHTSA data you provided: there are No NHTSA complaints found for this make/model/year/issue combination, and No recalls found in the NHTSA database for this make/model. I will not cite recalls/TSBs beyond what you supplied. All repair cost estimates reflect typical 2025 market prices and may vary by region, trim, engine, and labor rate. Data limitations: the available data do not include complaint counts or recall/regulatory entries for this specific code on this model, so I’ll rely on general automotive diagnostic practice for P0302.

CODE MEANING AND SEVERITY

• Code meaning: P0302 = Cylinder 2 misfire detected. The engine control module (ECM/PCM) has detected that cylinder 2 did not fire as expected during combustion, triggering the misfire diagnostic.
• Severity and implications:
  • Mild misfire may cause rough idle or slight stumble; fuel economy and performance may be reduced.
  • Repeated or severe misfires can overheat the catalytic converter and may lead to catalytic damage, increased emissions, and potential engine damage if not addressed.
  • The Malfunction Indicator Lamp (MIL) may be solid or flashing depending on factory logic and driving conditions.
• Data note: No complaints or recalls were reported in the provided dataset for this specific issue on 2019–2023 Cherokee, so there are no official case-specific mitigation notes from that dataset to cite here.

COMMON CAUSES ON JEEP CHEROKEE

P0302 is caused by a problem affecting cylinder 2’s ability to ignite and/or burn air/fuel properly. Typical Cherokee-specific and general causes include:

• Ignition system
  • Faulty spark plug in cylinder 2 (worn, fouled, or damaged)
  • Bad ignition coil on cylinder 2 or a faulty coil-on-plug ignition coil pack/wiring for cylinder 2
  • Damaged or loose spark plug boot/coil connector
• Fuel system
  • Faulty or dirty fuel injector for cylinder 2 (stuck open/closed, not spraying properly)
  • Low fuel pressure or intermittent fuel supply to cylinder 2
  • Fuel injector O-rings/leakage causing a lean/rich condition on that cylinder
• Air and intake
  • Vacuum leak near cylinder 2 (PCV hoses, intake manifold gasket, vacuum lines)
  • Mismatched or dirty mass airflow sensor (less common for isolated cylinder misfires but can contribute to overall imbalance)
• Compression and mechanical
  • Low compression in cylinder 2 due to valve issue, piston ring wear, scoring, or a head/gasket concern
  • Timing chain/belt/timing variation issues (less common but possible in some engines)
• Electrical/wiring
  • Damaged wiring harness or connector to cylinder 2 coil or injector
  • PCM/grounding issues that affect cylinder 2 fuel/ignition control (rare, but possible)
• Engine design considerations
  • Direct-injection engines (common on several Cherokee engines) can show misfires if carbon buildup or injector issues impact cylinder performance
• Note: In many Cherokees, a single-cylinder misfire (P0302) is most often traced to spark/coil or injector problems, with mechanical causes considered if the basic checks don’t reveal a fault.

SYMPTOMS

• Check Engine Light (MIL) active with P0302 stored; may be accompanied by other misfire codes (P0300, P0301, P0303, etc.) if the issue alternates or is broader.
• Rough idle or stumble, especially at idle or low speed
• Loss of power or hesitation under acceleration
• Degraded fuel economy
• Engine vibration or surging on idle
• Occasional misfire events that happen more prominently under load or during start-up
• In some cases, you may not notice symptoms beyond a MIL, particularly if the misfire is intermittent

DIAGNOSTIC STEPS

A systematic approach helps identify the root cause. The steps below assume you have basic hand tools and access to a scan tool and standard diagnostic equipment.

Step 0 – Confirm and scope

• Use a good OBD-II scan tool to confirm P0302 and check for related codes (P0300, P0301, P0303, P0304, etc.). Note freeze-frame data (engine RPM, load, temperature, misfire counts) for context.
• Note driving conditions when the misfire occurs (idle vs. load, cold start vs. hot engine).

Step 1 – Visual inspection

• Inspect cylinder 2 ignition components:
  • Spark plug: condition, gap, fouling, oil contamination
  • Ignition coil on cylinder 2 and its boot/connector for damage or corrosion
• Inspect cylinder 2 fuel injector wiring and connector for corrosion or looseness
• Inspect for obvious vacuum leaks around the intake manifold and PCV system near cylinder 2
• Check for oil leaks near the cylinder that could foul a plug or coil

Step 2 – Spark plug and ignition coil testing

• Spark plug: If fouled or worn, replace (preferably all plugs if the engine uses a common-usage spark plug pattern). Check the gap to OEM spec.
• Coil on plug (COP) test:
  • Swap test (swap the coil from cylinder 2 with another cylinder’s COP that you know is functioning well; re-scan to see if P0302 follows the coil). If the code moves to the other cylinder, the coil is likely bad.
  • Electrical test: measure primary/secondary resistance against factory specs (if available for your engine). A bad coil typically shows abnormal resistance or an open/short.
• If the spark plug and coil test normal, proceed to fuel and compression checks.

Step 3 – Fuel injector testing (cylinder 2)

• Check injector resistance/spec with intended OEM spec; abnormal resistance can indicate a faulty injector.
• Perform a live test if possible:
  • Use a noid light or injector pulse tester to verify that the PCM is firing the injector for cylinder 2.
    If possible, swap the injector from cylinder 2 with another cylinder’s injector to see if the misfire follows the injector.
• Listen for a ticking injector using a mechanic’s stethoscope; absence of ticking may indicate injector not energizing or a clogged/inoperative injector.

Step 4 – Fuel pressure and pump/rail considerations

• Measure fuel rail pressure with a fuel pressure gauge to ensure it’s within the engine’s specified range for the operating condition.
• If pressure is low or fluctuating, investigate the fuel pump, fuel filter, pressure regulator, and potential leaks in the fuel system.

Step 5 – Air and vacuum integrity

• Perform a vacuum test to check for leaks around the intake manifold, throttle body, and associated hoses that could affect cylinder 2.
• If applicable, inspect intake manifold gaskets and PCV lines near cylinder 2 for leaks.

Step 6 – Compression and mechanical condition

• Perform a compression test on cylinder 2 (and ideally on all cylinders to compare). Look for significant deviations from the others.
• If compression is low, perform a leak-down test to identify where the loss is occurring (valve, piston, head gasket, etc.).

Step 7 – Data analysis and cross-checks

• Review engine operating conditions (cold vs hot), misfire behavior (steady vs intermittent), and whether the misfire occurs at idle, during acceleration, or at specific RPMs.
• If other misfire codes appear (P0300 or P0301/3/4/5/6), this suggests a broader issue, such as fuel delivery or ignition system problems across cylinders.
• If all physical tests pass, consider PCM-related issues or less common causes, and consider professional software/diagnostic tools to check for calibration or wiring faults.

Step 8 – Decision point

• If you identify a failed spark plug, coil, or injector on cylinder 2, replace the faulty part and re-test.
• If testing reveals no obvious fault but misfire persists, consider more extensive mechanical diagnosis or professional service, including possible head gasket or compression-related repairs.

Related codes

• P0300 – Random/multiple misfires
• P0301 – Cylinder 1 misfire
• P0303 – Cylinder 3 misfire
• P0304 – Cylinder 4 misfire
• P0305 – Cylinder 5 misfire
• P0306 – Cylinder 6 misfire
  Notes: These codes indicate misfires in other cylinders or a pattern of misfire that could help pinpoint if the issue is ignition/fuel system-wide or localized.

REPAIR OPTIONS AND COSTS (2025 prices)

Prices vary by engine (4-cylinder vs V6), trim, region, and labor rates. The following are general ranges for common repairs related to P0302 on 2019–2023 Jeep Cherokee:

• Basic diagnostic service

  • Typical cost: $100–$200 (if performed at a shop; some shops may include diagnostic with repair)

• Spark plug replacement (cylinder 2; usually 4-cylinder 2.4L or 6-cylinder engines differ)

  • Parts: $4–$40 for a set (depending on engine; individual plugs can be cheaper or more expensive depending on iridium/platinum type)
  • Labor: $60–$150
  • Total (single cylinder replacement vs all plugs): If you replace just cylinder 2, you might spend $100–$220; if you replace all plugs (common when one misfire occurs in engines with 4–6 plugs), total can be $150–$350 or more
  • Note: For most V6 Cherokee engines, many technicians recommend replacing all spark plugs at the same time to ensure even wear and to avoid future misfires due to worn plugs.

• Ignition coil on cylinder 2 (coil-on-plug)

  • Parts: $50–$180
  • Labor: $40–$150
  • Total: $90–$330
  • Tip: If the misfire follows a specific coil in a swap test, replacing the faulty coil is usually sufficient.

• Fuel injector (cylinder 2)

  • Parts: $120–$350
  • Labor: $80–$180
  • Total: $200–$520
  • Note: If the injector is dirty or partially clogged, a cleaning service may be cheaper (see below).

• Fuel system cleaning / injector cleaning

  • Parts: minimal
  • Labor: $60–$180
  • Total: $60–$200
  • This is a reasonable interim measure if the injector calibration is not confirmed defective and there’s no obvious mechanical failure.

• Fuel pressure issue (pump, regulator)

  • Fuel pump replacement (if needed): Parts $100–$350; Labor $300–$900 depending on access
  • Total: $400–$1250
  • Fuel pressure regulator and related lines: typically part of fuel rail assembly in modern engines; costs similar to pump replacement if replaced

• Mechanical/engine repair (compression issues, valve, head gasket)

  • Typical ranges: $1000–$4000+ depending on extent (valve job, head work, or major engine work)
  • These are less common for a single-cylinder misfire unless compression tests show substantial loss.

• Optional/maintenance-focused steps

  • PCV valve or hose replacement: $40–$120 parts; $60–$200 labor
  • Intake cleaning or carbon cleaning (valve/port): $150–$500 depending on engine and method
  • ECU/PCM reprogramming or software update: $0–$150 (depending on dealer/independent shop; some updates are included with service campaigns)

Notes on pricing:

• Prices shown are approximate ranges for typical repair shops in 2025. Regional labor rates and parts pricing will affect final numbers. In some cases, dealers may charge more for OEM parts and specialized diagnostics.

DIY vs PROFESSIONAL

• DIY-friendly elements (if comfortable with basic automotive work):
  • Replacing spark plugs (for 4-cylinder or 6-cylinder engines, following proper torque specs and gap)
  • Replacing a faulty ignition coil on cylinder 2 if you can access the coil pack and follow safety precautions
  • Inspecting and reseating electrical connectors to the coil and injector
  • Visual inspection of wiring and vacuum hoses; performing a basic compression test with a gauge (if comfortable)
  • Fuel injector cleaning (using appropriate fuel system cleaners) and a basic injector test with a noid light
• When to go professional:
  • If the misfire persists after replacing plugs and coil
  • If you suspect a faulty fuel injector (requires accurate testing and possibly removing the injector)
  • If fuel pressure is out of spec or you suspect a failing pump or regulator
  • If compression testing indicates mechanical problems (low compression on cylinder 2)
  • If direct injection carbon buildup or valve issues are suspected (requires specialized tools and procedures)
• Safety and complexity notes:
  • Modern Cherokees with direct injection and coil-on-plug systems require caution with high-pressure fuel systems and electrical harnesses.
  • If you’re not comfortable with fuel system pressure, coil resistance testing, or compression tests, consider professional service.

PREVENTION

• Regular maintenance aligned with the owner’s manual:
  • Replace spark plugs at the recommended intervals (engine-specific; many engines in Cherokees use long-life plugs, but follow the OEM schedule)
  • Use quality fuel and avoid poor-quality fuel; consider a fuel system cleaner if recommended by your maintenance plan
  • Replace ignition coils if symptoms of coil failure appear (misfires, rough idle, or change in spark performance)
  • Keep air filters clean to ensure proper air/fuel mixture
• Monitor for early signs of misfires:
  • If you notice rough idle, engine stumble, or MIL illumination, address promptly to avoid catalyst damage
• For direct-injection engines:
  • Be mindful of carbon buildup on intake valves; periodic professional cleaning can help prevent misfires associated with carbon build-up in some engines
• Software and calibration:
  • Ensure ECU/PCM software is up to date as per dealer recommendations; software updates can address misfire detection behavior in some cases

DATA LIMITATIONS AND TAKEAWAYS

• Based on your provided data, there are no NHTSA complaints or recalls for this exact issue on 2019–2023 Jeep Cherokee. That means no model-wide recall or complaint-driven guidance is included here.
• The diagnostic and repair guidance above uses standard misfire diagnostic practices applicable to most modern engines and is tailored to the Cherokee’s engine configurations (4- and 6-cylinder variants common in 2019–2023 models). If your Cherokee uses a different engine variant, adapt component locations (spark plugs, coil packs, injectors) accordingly.
• If you’re uncertain about engine variant or exact cylinder layout, consult your vehicle’s service manual or a qualified technician for cylinder numbering and torque/gap specifications.

Quick reference checklist for P0302 on a Cherokee

• Confirm P0302 with a scan tool; note any accompanying codes.
• Inspect and test spark plug and ignition coil on cylinder 2; consider swapping test to isolate coil or plug.
• Check cylinder 2 injector operation and resistance; verify PCM control signal.
• Validate fuel pressure to ensure adequate supply to all cylinders; check for leaks.
• Check for vacuum leaks around cylinder 2; inspect hoses and valve covers.
• Perform a compression test for cylinder 2 to rule out mechanical issues.
• If problem persists after component-level fixes, consider more extensive mechanical diagnostics or professional service.