1. What is P0307 in Ford F-150?

P0307 is an OBD-II Diagnostic Trouble Code defined as Cylinder 7 Misfire Detected. For the Ford F-150—America’s best-selling vehicle for 40+ years—this code signals the engine’s 7th cylinder is failing to ignite fuel properly, critical for maintaining power during towing (up to 14,000 lbs) and heavy hauling in the 6.2L V8 (L87) and 5.0L V8 (Coyote) engines.

F-150’s ECM uses crankshaft position sensors to detect misfires—when Cylinder 7’s combustion doesn’t contribute to engine rotation, the code triggers. P0307 is widespread in 2019-2023 F-150 models, addressed in Ford Technical Service Bulletin (TSB) 21-2367 for faulty ignition coils in 6.2L Raptor and Limited trims, and carbon buildup in 5.0L Coyote engines.

2. Common Causes in 2018-2024 F-150 Models

P0307 in F-150s ties to V8 engine stress and component wear—here are MA200 V6-diagnosed cases:

• Faulty Ignition Coil (2020 F-150 Raptor 6.2L): A Raptor owner with 68,000 miles noticed rough idle during towing. MA200 V6’s Cylinder Misfire Test confirmed 7th cylinder失火 (12+ misfires per minute). Heat from towing degraded the coil’s windings—replacing with OEM #BL3Z-12029-A fixed combustion.
• Worn Spark Plugs (2021 F-150 Limited 5.0L): A Limited owner’s P0307 appeared with reduced acceleration. MA200 V6’s Ignition System Test showed Cylinder 7’s spark plug gap at 0.070" (spec: 0.044"). Extended use (80,000 miles) widened the gap—installing OEM #SP-540 plugs restored ignition.
• Clogged Fuel Injector (2019 F-150 XL 5.0L): An XL owner’s P0307 paired with fuel odor. MA200 V6’s Fuel Injector Balance Test showed Cylinder 7’s injector flow at 60% of target. Carbon deposits from short trips clogged the injector—cleaning with Ford-approved cleaner (#XC-20) resolved flow issues.
• Intake Valve Carbon Buildup (2022 F-150 King Ranch 5.0L): A King Ranch owner’s P0307 was intermittent. MA200 V6’s Intake Manifold Pressure Test showed restricted airflow to Cylinder 7. Direct injection carbon buildup blocked the valve— walnut blasting (per TSB 21-2367) restored airflow.

3. Key Symptoms in Ford F-150

P0307 symptoms in F-150s worsen under load—watch for these signs, especially when towing or hauling:

4. F-150 Engines/Trims Prone to P0307

Ford service data highlights these 2018-2024 F-150 configurations with highest P0307 rates:

5. Diagnostic Steps with ICARZONE MA200 V6

Diagnose P0307 in your F-150 accurately with MA200 V6’s Ford-specific tools—follow these steps (critical: do not drive if Check Engine Light flashes):

Case Example: A 2020 F-150 Raptor 6.2L failed Step 2 (18 misfires/min) and Step 3 (3.2Ω coil resistance). MA200 V6’s Component Location guided access to Cylinder 7’s coil (driver’s-side rear, remove engine cover). Replacing the OEM coil fixed P0307—verified by test drive (no misfires during 7,000-lb towing).

6. Fixes for F-150's P0307

Resolve P0307 in your F-150 with these MA200 V6-verified fixes (match to diagnosis results):

1. Replace Cylinder 7 Ignition Coil (6.2L Raptor/Limited)

1. Confirm coil failure via MA200 V6’s COP Test—disconnect battery first (safety: 12V system).
2. Locate Cylinder 7 coil (F-150 V8: driver’s-side bank, rear position—remove engine cover if equipped).
3. Unplug coil connector (press tab) and remove coil (pull straight up—use slight wiggling if stuck).
4. Install OEM coil (critical: do not use aftermarket—fails in 6+ months):
   • 6.2L (2019-2023): #BL3Z-12029-A
   • 5.0L (2018-2024): #BL3Z-12029-B
5. Reconnect battery, clear codes with MA200 V6, and test idle (no shakes = success). For towing models: Test with 500-lb load to verify.

2. Replace Spark Plugs (5.0L Coyote Models)

1. Confirm wear via MA200 V6’s Ignition System Test—let engine cool 1+ hour (hot plugs = burn risk).
2. Remove Cylinder 7 ignition coil (Step 2 above) to access the spark plug.
3. Remove old plug with a 5/8" spark plug socket (use extension—F-150 5.0L: deep well needed).
4. Install OEM #SP-540 plugs (gap to 0.044")—apply anti-seize to threads (avoid electrode).
5. Torque to 18 ft-lbs, reinstall coil, and perform MA200 V6’s Misfire Relearn function (critical for 5.0L).

3. Clean Fuel Injector/Intake Valves (Clog/Buildup)

1. Injector Cleaning (all models): Add Ford-approved injector cleaner (#XC-20) to a full tank—drive 100+ miles (highway preferred) to dissolve deposits. Verify with MA200 V6’s Injector Balance Test.
2. Intake Valve Cleaning (5.0L): For carbon buildup (per TSB 21-2367), use walnut blasting service (DIY not recommended—risk of engine damage). Ford dealers charge $350–$500; verify with MA200 V6’s Manifold Pressure Test post-service.

7. Repair Costs & Maintenance Tips

F-150 P0307 repair costs vary by cause—use this table to budget (note: flashing Check Engine Light = urgent repair, avoid driving):

Maintenance Tips for F-150 Owners

• 6.2L Raptor/Limited: Replace ignition coils every 80,000 miles (preventive, per TSB 21-2367)—replace all 8 if one fails (matching coils = balanced performance).
• 5.0L Coyote: Replace spark plugs every 60,000 miles (OEM #SP-540 only) and add fuel injector cleaner (#XC-20) every 10,000 miles to reduce carbon.
• Towing-focused models: Inspect Cylinder 7 coil/wiring after every 5,000 miles of towing—heat accelerates wear; use dielectric grease on coil connectors.
• 2021+ Raptor R: Use Top Tier gasoline (e.g., Shell V-Power) to minimize injector clogging—high-performance engines are sensitive to fuel quality.
• Perform MA200 V6’s Cylinder Misfire Check quarterly (especially before towing season) to catch issues early—avoids costly catalytic converter damage ($1,800+).

8. Preventive Maintenance for Ford F-150

Avoid P0307 in your F-150 with these Ford-recommended steps, tailored to V8 engines and towing use:

• Ignition System Care:
  • For 6.2L models: Use only OEM ignition coils (#BL3Z-12029-A)—aftermarket coils overheat under towing load (fail in 6–12 months).
  • Apply dielectric grease to coil connectors annually—prevents corrosion from road salt (critical for Rust Belt owners).
  • Inspect coil wiring every oil change—towing vibration can loosen connectors; secure with zip ties if needed.
• Spark Plug & Fuel System Maintenance:
  • 5.0L Coyote: Gap spark plugs to exactly 0.044"—over-gapping causes misfires; under-gapping reduces power.
  • All models: Add Ford Fuel System Cleaner (#XC-20) to a full tank every 10,000 miles—dissolves injector deposits and intake carbon.
  • Avoid letting fuel level drop below 1/4 tank—low fuel causes the pump to work harder, leading to inconsistent injector flow.
• Engine & Intake Care:
  • 5.0L models: Schedule walnut blasting every 100,000 miles (per TSB 21-2367)—prevents intake valve carbon buildup that blocks airflow to Cylinder 7.
  • Change engine oil every 5,000 miles (towing use) or 7,500 miles (light use)—use 5W-30 full synthetic (#XO-5W30-Q1) for 5.0L/6.2L.
  • Inspect intake manifold gaskets every 60,000 miles—leaks let unfiltered air enter, causing lean conditions and misfires.
• Towing Habits:
  • Never exceed F-150’s max towing capacity (6.2L: 14,000 lbs; 5.0L: 11,500 lbs)—overloading stresses ignition/fuel components.
  • Warm the engine to 195°F before towing—cold engines have incomplete combustion, increasing carbon buildup.
  • Use "Tow/Haul Mode" when towing—adjusts shift points to reduce engine load, minimizing misfire risk.

9. F-150-Specific FAQs