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What P0302 means for your Ford F-150
Your F-150's ECM detected that cylinder 2 isn't firing properly - the crankshaft position sensor saw the rotational speed dip slightly each time cylinder 2 was supposed to combust. On the 5.4L 3V Triton (2004-2010), P0302 is famously the COP coil or spark-plug ejection. On 3.5L EcoBoost trucks, cyl-2 misfire usually points to a failed coil or carbon-fouled intake valve.
🎯 Top Causes on the Ford F-150
50%
#1 CAUSE
Coil-on-Plug Failure (5.4L 3V)
The 2004-2010 F-150 5.4L 3V Triton has eight individual COP coils that fail in a predictable pattern - cyl 2 (passenger-front) is a top-five failure spot due to its position next to the exhaust manifold. Motorcraft DG-511 is the OEM coil; many owners now use Motorcraft DG-521 (improved redesign) for $60-$95 each. Replace as a set if mileage is high - if one has failed, the others are queued up. Swap cyl-2 with cyl-6 first to confirm.
OEM Coil
$60-$95
Set of 8
$280-$540
w/Labor
$140-$280 (single)
30%
#2 CAUSE
Spark Plug Ejection or Broken Plug (5.4L 3V)
The 5.4L 3V is infamous for two plug issues: (1) the 2-piece plug design breaks when removed at 60k+ miles, leaving the lower electrode in the cylinder head; (2) the spark plug threads are weak aluminum and the plug can blow out of the head under combustion pressure, taking the coil and threads with it. If you hear a sudden loud pop and lose power, you likely ejected a plug. Use a borescope to inspect the cyl-2 plug threads. The fix is a Time-Sert or Big-Sert thread repair kit - DIY-able with patience.
Time-Sert Kit
$120-$220
Plug Extraction Tool
$40-$80
Shop Thread Repair
$300-$600
20%
#3 CAUSE
Carbon-Fouled Intake Valve (3.5L EcoBoost)
The 3.5L EcoBoost is direct-injection only (no port injectors before 2017), so the intake valves accumulate carbon from PCV vapors with no fuel wash to keep them clean. By 80k miles the cyl-2 valve can have enough carbon buildup to cause incomplete sealing and a steady misfire. Symptoms: misfire only under boost, normal idle. Fix is a walnut-blast intake-valve cleaning - $400-$700 at a shop, or 4 hours DIY with a $200 blaster.
Walnut Blast (DIY)
$80-$200
Walnut Blast (Shop)
$400-$700
Set of Coils
$140-$280
🚗 Most Affected F-150 Model Years
| Year | Engine | Primary Cause | Typical Mileage | Notes |
|---|---|---|---|---|
| 2004-2010 | 5.4L 3V Triton V8 | Coil + plug ejection | 60k-120k | Highest P0302 reports |
| 2011-2017 | 3.5L EcoBoost V6 | Coil or carbon | 70k-130k | DI carbon at 80k+ |
| 2011-2020 | 5.0L Coyote V8 | COP coil | 90k-150k | Very reliable; rare P0302 |
| 2015-2020 | 2.7L EcoBoost V6 | Coil or injector | 60k-110k | Has port + DI injection |
🔧 How to Diagnose P0302 on a Ford F-150
- Swap cyl-2 coil with cyl-6 (easy access on V8). Clear code, drive 5 minutes. Misfire follows = bad coil. Total cost: 15 minutes and one socket wrench.
- On a 5.4L 3V, before removing a spark plug, soak the well with PB Blaster overnight and only remove plugs warm (not hot, not cold). Use Lisle 65600 broken plug extractor on hand. If the plug snaps, the lower electrode must be removed before you can install a new plug.
- On a 3.5L EcoBoost, inspect intake valves with a borescope. Heavy black coke on the valve back = walnut blast time. Also check for misfire only under boost vs at idle - boost-only misfire on a single cylinder is the textbook carbon symptom.
Want a step-by-step walkthrough specific to your Ford F-150? Run a $5.99 AI diagnosis report - we narrow the cause to your year, engine, and symptoms.
❓ Frequently Asked Questions
How much does P0302 cost to fix on an F-150?
5.4L 3V coil only: $140-$280. 5.4L plug ejection with thread repair: $300-$600. 3.5L EcoBoost coil: $140-$280. 3.5L EcoBoost carbon cleanup: $400-$700. Coyote 5.0L coil: $160-$300. EcoBoost carbon is the most expensive non-emergency fix.
Why does the 5.4L Triton break spark plugs?
The 5.4L 3V uses an unusual two-piece spark plug (Motorcraft SP-515 / SP-546) with a long lower electrode that carbon-welds itself into the cylinder head. When you try to unscrew the plug, the lower piece snaps off and stays in the head. Ford issued a special extraction procedure (TSB 08-7-6) using Rotella T penetrant and a Lisle 65600 extractor.
Can I drive my F-150 with P0302?
Short distances only. A steady CEL means intermittent misfire - drive to the shop and fix it. A flashing CEL means active severe misfire - pull over and tow, or you'll ruin the catalytic converter (cat replacement on an F-150 runs $800-$2000+).
Which cylinder is cylinder 2 on a 5.4L Triton V8?
On Ford modular V8s, cylinders 1-2-3-4 are the passenger-side bank (front to back) and 5-6-7-8 are the driver-side bank. Cyl 2 is the second from the front on the passenger side - easy to reach from above.
Should I replace all 8 coils on a 5.4L if one fails?
If the truck has over 100k miles, yes - the others are within months of failure. Doing all 8 at once costs about $280-$540 in parts vs $60-$95 single. Saves you four future shop visits.
See all P0302 causes (all vehicles) → · Related: Ford 5.4L Triton Spark Plug Problems →