P0302 Code: Chevrolet Silverado (2019-2024) - Causes, Symptoms & Fixes

Comprehensive diagnostic guide for OBD-II code P0302 on Chevrolet Silverado (model years 2019–2024)

Important data note

• REAL NHTSA data provided: No owner complaints, no official recalls found for this make/model/year/issue combination.
• Because there are no recalls or complaint data in the supplied dataset, this guide relies on general automotive knowledge and typical Silverado-specific failure modes rather than NHTSA-reported recalls/TSBs.
• If you do find a service bulletin (TSB) or recall that applies to your exact VIN, follow the manufacturer guidance. Otherwise, treat this as a practical diagnostic reference built on common misfire causes and typical diagnostic workflows.

CODE MEANING AND SEVERITY

• What P0302 means: P0302 is an OBD-II diagnostic trouble code that indicates a misfire detected in cylinder 2. The engine control module (ECM/PCM) has detected abnormal combustion in cylinder 2 and has logged a misfire.
• Severity and impact:
  • A misfire can cause rough running, reduced power, and poor fuel economy.
  • Prolonged misfires can damage the catalytic converter due to unburned fuel entering the exhaust.
  • In some conditions (e.g., heavy load or high RPM), misfires can trigger engine damage if left unaddressed.
• Typical action by the PCM: In many cases, the ECM will shut down the affected cylinder to protect itself and the catalytic converter, resulting in reduced power and a Check Engine light.

COMMON CAUSES ON CHEVROLET SILVERADO (2019–2024)

• Ignition-related causes (most common):
  • Faulty spark plug in cylinder 2 (fouled, worn gap, damaged electrode).
  • Faulty ignition coil on cylinder 2 or its wiring/connector (coil-on-plug arrangement is typical on modern Silverado engines).
  • Damaged or corroded coil harness/wiring to the coil pack.
• Fuel delivery/injection causes:
  • Faulty fuel injector for cylinder 2 (sticking, clogged, or leaking).
  • Low fuel pressure affecting injector performance (pump, filter, or regulator issues).
• Air and vacuum-related causes:
  • Vacuum leak near or affecting cylinder 2 (gasket, hose, or runner leaks).
  • Intake manifold leaks or cracked plenum on the bank that includes cylinder 2.
• Mechanical/compression-related causes:
  • Low compression in cylinder 2 due to worn rings, valve issues, or head gasket problems (less common but possible).
• Sensor/ECU-related causes:
  • Faulty cam/ crank position sensor or irregular injector pulse timing affecting cylinder 2.
  • Wiring/connector fault to a sensor or actuator tied to cylinder 2 misfire.
• Other notes:
  • Misfires can be condition-dependent (e.g., under load, at idle, cold start) and sometimes alternate cylinders show misfire in the PCM logs if the root cause is fuel/air delivery or ignition rather than a mechanical issue.

SYMPTOMS YOU MIGHT NOTICE

• Rough idle or vibration at idle, especially when the engine is cold or under light load.
• Hesitation or stumble during acceleration; reduced power.
• Noticeable decrease in fuel economy.
• Check Engine Light (cel) or Malfunction Indicator Lamp (MIL) is on or flashing (a flashing MIL typically indicates misfire under load and may require immediate attention to avoid damage).
• Potential improvements or worsening with plug/coil replacement or injector testing (if symptoms move to another cylinder after swapping components).

DIAGNOSTIC STEPS (step-by-step workflow)

Prepare safely: Park on a level surface, engine off, disconnect battery if required for certain tests, and use proper PPE. Have a diagnostic scanner that can read live data and misfire counters.

A. Confirm the basic problem

• Read DTCs with a scan tool: Confirm P0302 and check for any additional codes (P0300 is common when multiple misfires or intermittent misfires occur).
• Review freeze-frame data to understand operating condition (engine load, RPM, fuel trim, temperatures).

B. Inspect ignition and fuel-delivery components (start with the most common causes)

• Inspect cylinder 2 spark plug:
  • Remove and inspect the spark plug for signs of fouling, oil in the plug well, excessive wear, or improper gap.
  • If the plug is fouled or worn, replace it with the correct OEM/quality plug and gap to spec.
• Inspect ignition coil and coil harness for cylinder 2:
  • Check coil on plug coil for signs of damage or arcing.
  • Inspect the secondary/primary resistance of the coil per GM service spec; check connector for corrosion or damaged pins.
  • If you have a known-good spare coil, perform a swap test (swap coil from cylinder 2 to another known good cylinder and observe whether the misfire follows the coil).
• Inspect the wiring/ connector to cylinder 2 coil and injector:
  • Look for damaged insulation, loose connectors, or corrosion.

C. Perform a swap or swap-test approach

• Coil/Plug swap test (recommended first step for ignition issues):
  • Move the coil (or complete coil-on-plug assembly) from cylinder 2 to another cylinder (e.g., cylinder 4) or swap plugs with a neighboring cylinder.
  • If the misfire moves to the new cylinder, you’ve identified the faulty ignition component (coil or plug).
• Injector test (if ignition tests don’t confirm a bad coil/plug):
  • Listen for injector operation on cylinder 2 with a mechanic’s stethoscope or use a noid light to verify injector pulse signal.
  • Swap the injector for cylinder 2 with another cylinder’s injector. If misfire follows the injector, the injector is likely at fault.
  • Check injector resistance with a multimeter and compare to spec.

D. Check fuel delivery and air paths

• Fuel pressure test:
  • With the engine running within spec, measure fuel pressure at the rail using the appropriate sensor port. Compare to factory spec for your engine (the Silverado with multiple engines has different specs; follow the service manual).
  • If fuel pressure is low, diagnose pump, filter, and regulator; replace as needed.
• Vacuum/air leaks:
  • Perform a visual inspection for cracked vacuum hoses and gaskets near cylinder 2.
  • Use a smoke test or spray a small amount of brake cleaner around the intake, PCV, and manifold to identify leaks (if the engine RPM changes when sprayed, you’ve found a leak).

E. Check mechanical condition (compression/leak-down if ignition/fuel tests fail)

• Compression test on cylinder 2 (and compare with other cylinders):
  • If compression is significantly lower on cylinder 2, suspect mechanical issues (valve, piston rings, bore, head gasket, or a timing-related concern).
  • Wet compression test (add a small amount of oil into the cylinder and re-test) can help differentiate ring wear vs. valve/seal issues.
• If low compression is found, you may need further diagnostic steps (leak-down test, cylinder head work, or other repairs).

F. Consider sensor and engine-management concerns

• If ignition and fuel systems test normal but misfire persists, examine sensors that influence timing and fuel delivery. A faulty cam or crank sensor can cause intermittent misfires.
• Inspect the ECM/PCM connections and look for any software updates or reflash indications in service history.

G. Documentation and confirmation

• After performing the above, re-run the diagnostic with a scan tool to confirm P0302 is cleared or replaced by another cylinder misfire code (P0301, P0303, etc.) after component swaps. If the misfire persists but components were swapped, re-evaluate for a mechanical issue or a more complex electrical fault.

RELATED CODES

• P0300: Random/Multiple Cylinder Misfire Detected (not specific to cylinder 2).
• P0301, P0303, P0304, etc.: Misfire detected in other specific cylinders (1, 3, 4, etc.).
• P0352 (and other P035x codes): Ignition coil primary/secondary circuit malfunction for coil 2 (or the specific coil for your engine’s cylinder mapping). If you see P0352, inspect the coil, connector, and wiring to cylinder 2.
• Depending on engine variant, other related codes may appear (e.g., misfire-related codes coupled with lean/rich fuel trim codes like P0171 or P0174). Use the scan tool to assess fuel trim and sensor data alongside misfire codes.

REPAIR OPTIONS AND COSTS (2025 PRICES)

Note: Prices vary by region, shop, and engine variant. The ranges below assume Silverado 2019–2024 with common coil-on-plug ignition and direct-injected engines. SKU-level pricing can differ if your engine uses different spark plug types or injectors.

A. Quick ignition fix: replace spark plug and/or ignition coil on cylinder 2

• Spark plug (cylinder 2): parts typically $2–$15 each; total for one plug.
• Ignition coil (coil-on-plug, cylinder 2): parts typically $40–$120.
• Labor: approximately 0.5–1.0 hour (may be longer if access is tight for a specific engine).
• Estimated total: $100–$260 (parts + labor). If ignition coil and plug are replaced together, expect toward the higher end.

B. Ignition issue persists after plug/coil swap: injector-related fixes

• Fuel injector for cylinder 2: parts typically $100–$250.
• Labor: 1.0–1.5 hours.
• Estimated total: $180–$450.
• Optional: injector cleaning/services may be cheaper (e.g., injector cleaning kit service or professional cleaning) but is less definitive if the injector is actually failing.

C. Fuel system and air-path fixes

• Fuel pressure regulator, fuel pump, or fuel rail service: parts $50–$300; labor 1.0–2.0 hours.
• Vacuum leaks around cylinder 2 (gaskets, hoses, plenum): parts $10–$100; labor 0.5–2.0 hours; total roughly $100–$350 depending on parts and labor rates.

D. Mechanical/engine repairs (less common for P0302, but possible)

• Cylinder 2 compression issue (valve, head gasket, piston rings):
  • Minor valve seal repair or head gasket service: roughly $800–$2000 (labor-heavy, variable by engine).
  • Major mechanical issues (piston rings, scoring, or bore repair): $1500–$5000+.
• If timing chain/belt or tensioner issues contribute to misfire (engine-dependent): additional costs for timing components and labor.

E. Diagnostics and shop fees

• Diagnostic fee (if not waived with repair): typically $100–$150.
• Some shops waive diagnostic fees if you proceed with the repair at their facility.

F. Warranty considerations

• If vehicle is under factory or extended warranty, many of these items (ignition coils, spark plugs, injectors) may be covered depending on the issue and coverage terms. Always check with your dealer or warranty provider.

DIY VS PROFESSIONAL

• DIY-friendly scenarios:
  • Replacing a bad spark plug on cylinder 2 (and possibly the coil) is within reach for a capable DIYer with basic tools and knowledge of torque specs.
  • Swap-test ignition coil or spark plug to identify a defective component can often be done at home with basic hand tools and a spark plug wrench.
  • Visual inspection of connectors, hoses, and basic fuel-system checks (with proper safety measures) can be done by experienced DIYers.
• DIY caveats:
  • Modern Silverado engines with direct injection and COPs can be awkward to access; some engines require removing components or manifolds to reach cylinder 2 coils/plugs.
  • Working with high-pressure fuel systems or electrical components carries risk; disconnect the battery and follow proper safety procedures.
  • Misdiagnosis can lead to unnecessary parts replacement; a swap-test approach helps verify which component is at fault.
• When to use a professional:
  • If you suspect mechanical issues (low compression, valve problems, head gasket, timing chain issues) or you’re unable to identify the fault after ignition/fuel tests.
  • If symptoms persist after plausible ignition/fuel fixes, or if fuel pressure, compression tests, or injector testing require specialized equipment.
  • If you lack the tools or experience to safely diagnose and repair a modern direct-injected engine.

PREVENTION

• Regular maintenance:
  • Follow manufacturer-recommended spark plug replacement intervals for your engine variant (note: direct-injection engines may require attention to carbon buildup; use recommended plugs and torque specs).
  • Use good quality fuel and consider fuel injector cleaner products occasionally as directed by the vehicle’s owner manual, especially if your driving pattern includes many short trips.
  • Replace air filter, PCV valve, and intake components as specified.
• Keep ignition components healthy:
  • Periodically inspect coil-on-plug assemblies and wiring; replace aging coils if misfires recur on a specific cylinder.
• Monitor for early signs:
  • Address rough idle, stumbling, or decreasing fuel economy promptly to prevent catalyst damage or more serious engine issues.
• Fuel system health:
  • If you notice hard starts or fuel smell, examine the fuel system for leaks and maintain proper fuel pressure.
• Software updates:
  • Check for a GM software update or reflash if the dealership has issued one for misfire-related concerns (this is engine/PCM dependent).

Data limitations and transparency

• The provided data shows no recalls or official NHTSA complaints for P0302 on 2019–2024 Silverado in the supplied dataset. No recalls found in NHTSA database.
• This guide emphasizes diagnostic steps and common causes based on general Silverado engine architecture and common misfire patterns. Specific VIN-based issues, service bulletins, or recalls may exist outside the provided data; always verify with a GM dealer or official sources for your exact vehicle configuration.
• Costs are 2025 estimates and will vary by region, shop, engine variant, and labor rates. The ranges assume standard 8–12 cylinder equivalents and typical access for labor.