P0302 on 2011-2014 Chrysler 300 3.6L: Cylinder 2 Misfire Causes and Fixes

What's Unique About the 2011-2014 Chrysler 300

For 2011-2013 models with the 3.6L Pentastar V6, the P0302 code (along with P0304 and P0306) is a very strong indicator of a known manufacturing defect in the left cylinder head. This issue was so prevalent that Chrysler issued Technical Service Bulletin (TSB) 09-002-14 and extended the warranty on the part to 10 years or 150,000 miles under warranty extension code X56. The problem stems from premature wear of the valve seats and guides, which can lead to overheating of the cylinder's valve seats, causing a loss of compression and persistent misfires on the left bank of cylinders (2, 4, and 6). 🎬 Watch: A professional diagnosis of the P0302 cylinder 2 misfire. Chrysler began using redesigned heads with hardened valve guides and seats in production during the summer of 2012 to resolve the issue.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• Flashing or solid Check Engine Light
• Rough idle or shaking at a stop
• Engine hesitation or stumbling during acceleration
• Noticeable loss of power
• Decreased fuel economy
• Engine ticking noise (in cases of mechanical failure like cylinder head or rocker arms).
• Difficulty starting the engine.

Most Likely Causes

1. Defective Left Cylinder Head 🔴 High Probability A known manufacturing defect affected the valve guides and seats on 2011-2013 3.6L Pentastar engines, causing compression loss specifically on the left bank (cylinders 2, 4, 6). This was addressed by TSB 09-002-14 and warranty extension X56. While the warranty extension primarily covers 2011-2013 models, there are owner reports of the same failure on 2014 and later models, though often not covered by the extended warranty.
   How to confirm: After ruling out ignition and fuel issues, a cylinder leak-down test is the definitive diagnostic step. The TSB specifies that leakage of 25% or greater confirms the failure. A compression test may also show low pressure (e.g., 100psi) on the affected cylinder.
   Typical fix: Replacement of the left cylinder head assembly with a revised part. This is a major repair. The labor time is estimated to be around 8.2 hours for this platform.
   Est. part cost: $800-$1500
2. Failed Ignition Coil 🟡 Medium Probability
   How to confirm: Swap the ignition coil from cylinder 2 with another cylinder (e.g., cylinder 4). Clear the codes and drive the vehicle. If the code changes to P0304, the ignition coil is faulty. Another diagnostic trick is to unplug the coil on the suspect cylinder while the engine is running; if there is no change in how the engine runs, it confirms that cylinder isn't firing.
   Typical fix: Replace the faulty ignition coil. It's often recommended to replace the spark plug at the same time.
   Est. part cost: $30-$70
3. Worn or Fouled Spark Plug 🟡 Medium Probability
   How to confirm: Remove the spark plug from cylinder 2 and inspect it for wear, carbon buildup, or oil fouling. Compare it to a plug from a different cylinder. You can also swap the plug to another cylinder to see if the misfire follows it.
   Typical fix: Replace the spark plug. It is best practice to replace all six spark plugs at the same time, especially if they are near the end of their service life.
   Est. part cost: $10-$25 per plug
4. Faulty Fuel Injector ⚪ Low Probability
   How to confirm: Listen for a consistent clicking sound from the injector with a mechanic's stethoscope. You can also test the injector's resistance with a multimeter or swap it with another cylinder's injector to see if the misfire code moves. Some owners have resolved misfires by having the injectors professionally cleaned.
   Typical fix: Replace the faulty fuel injector.
   Est. part cost: $50-$120

Rare But Worth Checking

• Failed Rocker Arm/Lifter: The 3.6L Pentastar can also suffer from failed rocker arms, where the needle bearings in the roller collapse, causing excessive play. This can lead to a distinct ticking noise and eventually damage the camshaft, causing a misfire. A mechanic on a forum noted this is a common issue and can be mistaken for the cylinder head problem if not properly inspected. This issue is widespread across all vehicles using the 3.6L Pentastar.
• Corroded Spark Plug Tube: In rare cases specific to cylinder 2, corrosion inside the spark plug tube can cause the spark to ground out against the side of the tube instead of firing the plug, leading to a P0302 code.

Diagnosis Steps

1. Read the code: Use an OBD-II scanner to confirm P0302 and check for any other pending or stored codes, such as P0300, P0304, or P0306.
2. Check Freeze Frame Data: Note the engine conditions (RPM, load, temperature) when the misfire occurred.
3. Swap the Ignition Coil: Locate cylinder 2 (front-most cylinder on the driver's side). Swap the ignition coil with cylinder 4 (middle cylinder on the driver's side). This requires removing the upper intake manifold. Clear the codes and run the engine. If the code changes to P0304, the coil is bad.
4. Swap the Spark Plug: If the misfire remains on cylinder 2, move the spark plug from cylinder 2 to cylinder 4. If the code changes to P0304, the spark plug is bad.
5. Inspect the Fuel Injector: If the misfire still remains on cylinder 2, inspect the fuel injector's wiring and listen for its operation. Consider swapping it with another cylinder's injector if accessible.
6. Perform a Cylinder Leak-Down Test: If ignition and fuel components are ruled out, this is the crucial step for 2011-2013 models. Connect a leak-down tester to cylinder 2. According to Chrysler's TSB 09-002-14, if leakage is 25% or more, the cylinder head is faulty and requires replacement.
7. Inspect Valvetrain: If the leak-down test is within spec, remove the valve cover to visually inspect the rocker arms and camshaft lobes for abnormal wear, scoring, or damage. Check for excessive play in the rocker arm rollers, which indicates a bearing failure.

Parts You'll Likely Need

• Left Cylinder Head Assembly (OEM #RL141353AC) — This is the most probable cause for P0302 on 2011-2013 models due to a well-documented factory defect. This is the revised part number intended to fix the issue.
  Trusted brands: Mopar
  OEM price range: $1000-$1500
  Aftermarket price range: $800-$1200
• Ignition Coil (OEM #05149168AI) — A common failure point for any single-cylinder misfire. It's a relatively inexpensive and easy part to replace during diagnosis.
  Trusted brands: Mopar, NGK, Bosch
  OEM price range: $50-$80
  Aftermarket price range: $30-$60
• Spark Plug (OEM #SP149125AE) — Spark plugs are a routine maintenance item and a common cause of misfires. They should be inspected and likely replaced during diagnosis.
  Trusted brands: Mopar (NGK), Champion
  OEM price range: $15-$25
  Aftermarket price range: $8-$15
• Upper Intake Plenum Gaskets (OEM #05184562AC) — To access the spark plugs and coils on the driver's side (cylinders 2, 4, 6), the upper intake manifold must be removed. The gaskets should always be replaced when doing so.
  Trusted brands: Fel-Pro (MS 97204), Mopar
  OEM price range: $20-$40
  Aftermarket price range: $10-$25
• Lower Intake Manifold Gaskets (OEM #05184331AC) — These gaskets seal the lower intake manifold to the cylinder heads. They are also required to be replaced when removing the intake to access the driver's side bank and are listed as required parts in the TSB for the head replacement.
  Trusted brands: Fel-Pro (MS 97204), Mopar

Related Codes That Often Appear With This One

• P0300 — If the misfire is severe or intermittent, or if other cylinders on the same bank are also misfiring (like P0304 and P0306), the PCM may also log a P0300 'Random/Multiple Cylinder Misfire' code.
• P0304 — This code for a cylinder 4 misfire often appears with P0302 due to the common cylinder head issue affecting the entire left bank of the 3.6L engine.
• P0306 — This code for a cylinder 6 misfire often appears with P0302 for the same reason as P0304—the known cylinder head problem on the left bank.

Technical Service Bulletins (TSBs) & Recalls

• 09-002-14 Rev. B: 'MIL Illumination: P0300, P0302, P0304 or P0306 (X56 Warranty Extension)'. This is the primary TSB outlining the diagnosis (cylinder leak-down test) and repair (replace left cylinder head) for the known issue.
• Warranty Bulletin D-14-12: This bulletin officially announced the 10-year/150,000-mile warranty extension (X56) for the left cylinder head on affected 2011-2013 models.

Platform-Specific Known Issues

• Extended Warranty (X56) for Left Cylinder Head: Chrysler issued an extended warranty for the left cylinder head on 2011-2013 vehicles with the 3.6L engine, covering failure for 10 years or 150,000 miles. This specifically addresses misfire codes P0302, P0304, and P0306. Owners experiencing this issue should check with a Chrysler dealer using their VIN to see if their vehicle is covered under warranty extension X56. Some owners of 2014+ models have reported similar failures but were denied warranty coverage as the extension was year-specific.
• Alternator Failure Recall: While not directly causing P0302, a recall was issued for failing 160-amp alternators on 2011-2014 models which could cause the vehicle to stall. It's worth checking if this recall has been performed on your vehicle.

Mechanic-Grade Diagnostic Values

• Fuel Injector Resistance — expected: 11-14 Ohms. Failure: A reading significantly higher (e.g., double) or lower (open/short) than the expected range indicates a faulty injector winding.
• Ignition Coil Primary Resistance — expected: ~0.5 to 2.0 Ohms. Failure: A reading outside this range suggests a problem with the primary winding. However, this test is not always conclusive.
• Ignition Coil Secondary Resistance — expected: 6,000 - 10,000 Ohms (6k-10k Ω). Failure: A reading outside this range indicates a fault in the secondary windings.
• Fuel Pressure — expected: ~58 psi (400 kPa), +/- 5 psi. Failure: Low fuel pressure can cause lean misfires across multiple cylinders, but a failing pump could intermittently affect just one.

Hidden / Shadow Codes Worth Checking

• Mode 6, Component ID $A2: This is not a DTC, but a data parameter within OBD-II Mode 6 that shows raw misfire counts for Cylinder 2 for the current and last ten driving cycles. (see via Requires an advanced scan tool capable of reading Mode $06 data. A non-zero count confirms misfires are occurring, even if they aren't frequent enough to set a P0302 code yet.)

Scan Tool Commands That Help

• Chrysler wiTECH or equivalent professional scanner: Injector Kill / Cylinder Cutout Test — This bidirectional command allows the technician to manually disable the fuel injector for cylinder 2 while the engine is idling. If there is no change or a minimal drop in engine RPM when cylinder 2 is 'killed,' it confirms that cylinder was not contributing power, verifying the misfire.
• Chrysler wiTECH or equivalent: View Misfire Counters (Real Time) — Unlike the historical data in Mode 6, this live data PID shows misfires as they happen. It is invaluable for diagnosing intermittent misfires by observing the counter while performing actions like wiggling wires or changing engine load.

Wiring & Ground Locations

• Cylinder 2 Ignition Coil Connector — On the ignition coil for the front-most cylinder on the driver's side of the engine.. Testing for power and PCM signal occurs here. Pin 2 should have power from the ASD relay when the engine is running, and Pin 1 is the ground-side control signal from the PCM. A break in either wire will cause a misfire.
• G304 / G305 — Main engine-to-chassis grounds, often located on the right frame rail or near the right-side motor mount.. A poor or corroded main engine ground can cause a host of electrical issues, including weak spark or erratic sensor readings that can lead to misfires. Ensuring these are clean and tight is a crucial, often overlooked, step.
• Engine Harness (Under Intake) — The engine wiring harness, particularly the section for the knock sensors and oil sensors, runs in the valley underneath the lower intake manifold.. Though not directly for the ignition coil, this harness is exposed to high heat and oil leaks. A short in this harness can cause erratic PCM behavior and, in some cases, has been found to be the root cause of multiple seemingly unrelated codes.

Real Owner Repair Stories

• 300cforums.com user report (2014 Chrysler 300) — P0302, P0304, P0306 misfire codes.
  ❌ Tried (didn't work) Replacing spark plugs, Swapping ignition coils
  ✅ What actually fixed it The final repair was the replacement of all 24 rocker arms and lifters due to bearing failure, which is a known but separate issue from the cylinder head problem.
• ScannerDanner Forum user report (2014 Dodge Challenger 3.6L) — Constant P0302 misfire at idle and low RPM.
  ❌ Tried (didn't work) Swapping spark plug, Swapping ignition coil, Swapping fuel injector, Smoke test (no leaks found), Compression and leak-down tests (passed), Replacing lifters and rocker arms for cylinder 2, Having the cylinder head serviced at a machine shop
  ✅ What actually fixed it After extensive misdiagnosis, the problem was finally resolved by replacing the left cylinder head with a remanufactured unit from the dealer and also replacing all lifters and rocker arms for that bank. This suggests the original head had a subtle defect not caught by standard tests.

"I Checked Everything" — The Actual Cause

• In some cases, a P0302 misfire can be caused by a mechanically clogged or sticking fuel injector. This type of failure will not be detected by a smoke test (as there is no vacuum leak) and may even pass an electrical resistance test. The only way to confirm is by swapping the injector to another cylinder and seeing if the misfire follows, or by performing a flow test on the injectors.

OEM Part Supersession History

• 05184349AD / AE / AF → 05184349AG, and later revised designs such as RL141353AC (reman). — The original left cylinder heads were manufactured with valve guides and seats that would wear prematurely, leading to loss of compression and misfires on cylinders 2, 4, and 6.
  Heads up: Any replacement head should be a part manufactured after July 2012 (stamped with date code 2062 or higher) to ensure it is the revised, more durable design.

Model Year Variations Within This Range

• 2011-early 2013: These model years were built with the original left cylinder head design that is prone to failure. The P0302 code on these vehicles has a very high probability of being caused by the head defect.
• Late 2013-2014: These vehicles were built from the factory with the redesigned cylinder head, making the head failure a much less common cause for P0302. On these later models, a P0302 is more likely to be caused by a failed rocker arm/lifter, an ignition component, or a fuel injector.