P0306 on 2019-2021 Dodge Charger: Cylinder 6 Misfire Causes and Fixes

What's Unique About the 2019-2021 Dodge CHARGER

On the Dodge Charger, the root cause of a P0306 misfire often depends on the engine. The 3.6L Pentastar V6 has a documented history of left-bank cylinder head issues (affecting cylinders 2, 4, and 6), though this was more common in pre-2014 models. For 2019-2021 models, a P0306 with a ticking noise is more likely a failed rocker arm/cam follower, a very common issue for this engine generation. For the Hemi V8 engines (5.7L, 6.4L), a P0306 code can be a strong indicator of a failing lifter, particularly one related to the Multi-Displacement System (MDS), which can also damage the camshaft.

Diagnostic Flowchart

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

Symptoms You May Notice

• Rough or shaky idle.
• Hesitation or stumbling during acceleration.
• Noticeable loss of engine power.
• Flashing Check Engine Light (CEL).
• Reduced fuel economy.
• Audible ticking or knocking sound from the engine, especially with Hemi lifter issues or Pentastar rocker arm failure.

Most Likely Causes

1. Faulty Ignition Coil 🔴 High Probability Coil-on-plug systems are susceptible to failure from heat cycles and vibration over time. It's a common failure item on most modern engines.
   How to confirm: Swap the ignition coil from cylinder 6 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. Cylinder 6 on the 3.6L V6 is on the driver's side, rearmost position, and requires removing the upper intake manifold to access.
   Typical fix: Replace the faulty ignition coil. The Mopar part number is 5149168AJ (which supersedes 5149168AH and 5149168AI).
   Est. part cost: $40-$100
2. Worn Spark Plug 🔴 High Probability Spark plugs are a standard wear item. The recommended interval is typically 100,000 miles, but they can fail earlier.
   How to confirm: After ruling out the ignition coil, inspect the spark plug for cylinder 6. Look for wear, damage, or carbon fouling. Since accessing this plug requires removing the intake manifold on the V6, it's wise to replace all plugs on that bank (or all 6) at the same time.
   Typical fix: Replace the spark plug. It is recommended to replace all spark plugs at the same time for even performance. For the 5.7L Hemi, a common OEM plug is Mopar SP143877AA or its successor SP143877AB.
   Est. part cost: $10-$25 per plug
3. Failed MDS Lifter (Hemi V8 Engines) 🟡 Medium Probability The Multi-Displacement System (MDS) lifters in Hemi engines are a known failure point. The internal needle bearings can fail, causing the lifter to collapse or seize, which then often damages the camshaft lobe. This is often referred to as the 'Hemi Tick'.
   How to confirm: A persistent ticking noise that is loudest on a cold start and may quiet down as the engine warms is a strong indicator. A mechanic can confirm by removing the valve cover to inspect valve movement or, more definitively, by inspecting the lifters and camshaft.
   Typical fix: Requires replacing all lifters (MDS and non-MDS), the camshaft, and associated gaskets. This is a complex and expensive repair.
   Est. part cost: $1000-$2500 for a full cam and lifter kit
4. Failed Rocker Arm / Cam Follower (3.6L Pentastar V6) 🟡 Medium Probability This is a very common failure on the Pentastar engine across many Chrysler/Dodge/Jeep/Ram models. The needle bearings in the rocker arm roller can fail, leading to excessive play, a ticking noise, and eventually damage to the camshaft lobe, causing a misfire.
   How to confirm: A distinct ticking or tapping sound from the top of the engine, often louder on one side. The sound may be present at idle and increase with engine RPM. Diagnosis requires removing the valve cover on the respective bank (the left/driver's side for cylinder 6) to inspect for play in the rocker arms.
   Typical fix: Replace the failed rocker arm(s) and often the camshaft on that bank if it is scored or worn. It is highly recommended to replace all rocker arms 🎬 See this complete guided repair for Pentastar rocker arms and lifters on the affected head at the same time.
   Est. part cost: $200-$500 for rocker arms, lifters, and a new camshaft for one bank.
5. Faulty Fuel Injector ⚪ Low Probability
   How to confirm: If ignition and compression are good, the fuel injector is a likely suspect. You can test the injector's electrical circuit with a 'noid' light. A more definitive test is to swap the injector with another cylinder, but this is labor-intensive. A P0206 code may accompany the P0306 if the injector circuit has failed.
   Typical fix: Replace the clogged or failed fuel injector.
   Est. part cost: $70-$150

Rare But Worth Checking

• Cylinder Head Issue (3.6L Pentastar V6): An extended warranty (X56) was issued for 2011-2013 models for misfires on the left bank (cylinders 2, 4, 6) due to excessive valve guide/seat wear. The TSB (09-002-14 REV. B) directs technicians to perform a cylinder leak-down test; if leakage is 25% or greater, the left cylinder head must be replaced. While less common on 2019+ models which have revised heads, a persistent P0306 after checking ignition, fuel, and rocker arms warrants a compression and leak-down test to rule out a mechanical head issue.
• Low Engine Compression: Caused by issues like worn piston rings, leaking valves, or a damaged head gasket. A compression test is needed to diagnose this. A reading on cylinder 6 that is significantly lower than the other cylinders indicates a mechanical problem.
• Vacuum Leak: A leak from a cracked hose or a bad intake manifold gasket near cylinder 6 can lean out the air/fuel mixture, causing a misfire. A common, but often overlooked, source on the 3.6L V6 is a cracked plastic oil filter/cooler housing assembly, which sits in the valley of the engine and can cause a vacuum leak. A smoke test is the most effective way to locate a vacuum leak.

Diagnosis Steps

1. Scan the vehicle for any other trouble codes to get a complete picture.
2. For the 3.6L V6, access to cylinder 6 requires removing the upper intake manifold. For Hemi V8s, cylinder 6 is on the passenger side, third from the front.
3. Swap the ignition coil from cylinder 6 with an adjacent, easier-to-access cylinder. Clear the codes, run the engine, and see if the misfire code follows the coil (e.g., changes to P0304). If it does, the coil is bad.
4. If the misfire remains on cylinder 6, inspect and replace the spark plug. Since the intake is off on the V6, it's best practice to replace all 3 plugs on the driver's side bank.
5. For 3.6L V6: While the valve cover is accessible, listen for a distinct ticking sound. If present, remove the valve cover to inspect the rocker arms and camshaft for wear or damage. This is a very common failure point.
6. For Hemi V8s: Listen carefully for a ticking sound ('Hemi tick') that could indicate a lifter/camshaft problem, especially on cold starts.
7. If ignition components and valvetrain appear good, check the fuel injector on cylinder 6. Use a noid light to confirm it's receiving an electrical pulse.
8. If the problem persists, perform a compression test, followed by a cylinder leak-down test on cylinder 6. A low reading points to a mechanical issue (valves, piston rings, head gasket).
9. If all else fails, perform a smoke test to check for hard-to-find vacuum leaks, paying close attention to the intake manifold gaskets and the oil filter housing on V6 models.

Parts You'll Likely Need

• Ignition Coil (OEM #5149168AJ) — This is one of the most common failure points for a single-cylinder misfire. Heat and vibration cause the internal windings to fail over time.
  Trusted brands: Mopar, NGK, Denso
  OEM price range: $60-$100
  Aftermarket price range: $40-$75
• Spark Plug (OEM #SP143877AB (for 5.7L Hemi)) — Spark plugs are a routine maintenance item. The electrode wears down over time, leading to a weak or inconsistent spark.
  Trusted brands: Champion, NGK
  OEM price range: $15-$25
  Aftermarket price range: $8-$18
• Camshaft and Lifter Kit (Hemi V8) — A well-known issue on Hemi engines where a failing MDS lifter damages the camshaft lobe, requiring both to be replaced.

Related Codes That Often Appear With This One

• P0300 — If the misfire is intermittent or starting to affect other cylinders, a P0300 (Random/Multiple Cylinder Misfire) code may appear alongside P0306.
• P0302, P0304 — On the 3.6L V6, these codes may appear with P0306 if there is a systemic issue with the left cylinder head or valvetrain, as all three cylinders are on that bank.
• P0206 — This code indicates a fault in the fuel injector circuit for cylinder 6. If seen with P0306, it strongly points to the fuel injector or its wiring as the root cause.

Technical Service Bulletins (TSBs) & Recalls

• 09-002-14 REV. B: While for older models (2011-2013), this TSB confirms a history of left cylinder head failures on 3.6L engines causing P0300, P0302, P0304, and P0306. It instructs dealers to perform a cylinder leakage test and replace the head if leakage exceeds 25%, covered under an extended warranty (X56).
• 1400322REVA: Lists P0306 as a possible diagnostic code when a customer complains of a rough idle or misfire while driving.

Platform-Specific Known Issues

• Hemi V8 Camshaft/Lifter Failure: A P0306 code on a 5.7L or 6.4L Hemi, especially when accompanied by a ticking sound that is loudest on cold starts, is a strong symptom of a failed MDS lifter and worn camshaft lobe. This is a common and significant repair.
• 3.6L V6 Rocker Arm Failure: For the Pentastar V6, a ticking noise with a P0306 is very likely a failed rocker arm on the driver's side cylinder head. This is a widespread issue across all platforms using this engine. Inspection requires removing the valve cover.
• 3.6L V6 Cylinder Head Issue: Though a formal TSB (#09-002-14 REV. B) targeted earlier models (2011-2013), the left cylinder head (cylinders 2, 4, 6) on the Pentastar V6 remains a known weak point that can cause misfires due to valve train issues.

Mechanic-Grade Diagnostic Values

• Fuel Pressure (3.6L V6) — expected: 400 kPa +/- 14 kPa (58 psi +/- 2 psi). Failure: Pressure significantly below or above this range indicates a fuel delivery problem.
• Fuel Injector Resistance — expected: Approximately 12.3 ohms. Failure: A reading significantly higher (open circuit) or lower (shorted) than the others.
• Scan Tool Misfire Counter — expected: Zero or very few counts at idle and under load.. Failure: Rapidly increasing counts on cylinder 6, especially when power-braking the engine to simulate a load, confirms an active misfire.

Scan Tool Commands That Help

• High-end scanner (e.g., wiTECH, Autel, iCarsoft): Cylinder Power Balance / Misfire Counter — Use the live data stream to monitor misfire counts for each cylinder in real-time. This helps confirm the misfire is isolated to cylinder 6 and can show if it's intermittent or constant under specific loads (e.g., idle vs. acceleration).
• High-end scanner (e.g., wiTECH): ASD Fuel System Test — This bidirectional command actuates the fuel pump relay to allow for fuel pressure testing without the engine running, helping to diagnose fuel delivery issues.

Wiring & Ground Locations

• Cylinder 6 Ignition Coil Control Circuit — For a V8, this is Pin 1 of the C1 PCM connector.. If the coil and spark plug are good, a technician must test this circuit for an open, short to ground, or short to voltage between the PCM and the coil connector to rule out a wiring or PCM driver issue.
• Cylinder 6 Fuel Injector Control Circuit — For a V8, this is typically a dedicated pin on one of the main PCM connectors (e.g., C2 connector on older NGC systems). A specific wiring diagram for the exact year/engine is required for the correct pin.. A constant ground on this circuit, which can be caused by a failed PCM driver, will hold the injector open and flood the cylinder, causing a misfire.
• G910 / G911 — A primary ground point located behind the instrument cluster, to the left side of the dash.. This ground is used by the Powertrain Control Module (PCM). A poor ground connection here can cause erratic behavior from the PCM, including phantom misfire codes or incorrect sensor readings.

Real Owner Repair Stories

• Reddit user 'redgus78' on r/MechanicAdvice (2014 Chrysler Town & Country (shares 3.6L Pentastar engine)) — P0306 code and a rough idle.
  ❌ Tried (didn't work) Swapping ignition coils, Swapping fuel injectors, Replacing spark plugs, Compression test (was good), Leak down test (was good), Visually inspecting camshafts and valve train (no visible wear)
  ✅ What actually fixed it The problem was a worn exhaust rocker arm and a corresponding worn cam lobe on cylinder #6, which was not visually obvious upon initial inspection.
• Reddit user 'zparts' on r/Justrolledintotheshop (Dodge 5.7 Hemi (year not specified, but high mileage at 310k)) — P0306 misfire, but otherwise ran decently.
  ✅ What actually fixed it The cause was found to be damaged MDS (Multi-Displacement System) lifters which had, in turn, damaged the camshaft.
• RamForum.com user (Ram truck with Hemi engine) — P0306 code.
  ❌ Tried (didn't work) Swapping spark plugs, Swapping ignition coil
  ✅ What actually fixed it The final cause was a worn cam lobe due to a seized lifter roller on cylinder 6.

OEM Part Supersession History

• 5149168AH → 5149168AI, then 5149168AJ — Standard part revision and improvement by the manufacturer.