P0303 on 2014-2021 Dodge Charger: Cylinder 3 Misfire Causes and Fixes

What's Unique About the 2014-2021 Dodge CHARGER

For the 2014-2021 Dodge Charger, the cause of a P0303 misfire can differ between the 3.6L Pentastar V6 and the Hemi V8 engines (5.7L, 6.4L, 6.2L). While standard ignition components are the primary culprits on both, the Hemi engines are known for potential camshaft and lifter issues that can cause persistent misfires, sometimes referred to as the 'Hemi tick'. This failure often starts with a ticking noise and can escalate to a P0303 or P0300 code as the lifter's roller bearing fails and damages the camshaft lobe. The 3.6L Pentastar V6, particularly in later models (2016+), can also experience valvetrain issues, such as problems with rocker arms and lifters that cause a ticking noise and misfire, especially on cold startups.

Diagnostic Flowchart

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

Symptoms You May Notice

• Check engine light is on (solid or flashing)
• Rough or shaky idle
• Engine hesitation or stumbling during acceleration
• Noticeable loss of engine power
• Reduced fuel economy
• Smell of fuel from the exhaust
• Audible ticking or tapping sound from the engine, especially on cold starts (can indicate valvetrain issues)
• Remote start feature may be disabled when the check engine light is active

Most Likely Causes

1. Worn or Fouled Spark Plug 🔴 High Probability Spark plugs are regular maintenance items. Dodge recommends replacement at 100,000 miles for many of these engines, but they can fail sooner. A cracked porcelain insulator is also a common failure point that can cause a persistent misfire.
   How to confirm: Remove the spark plug from cylinder 3 and inspect it for wear, carbon buildup, oil fouling, or damage to the electrode or porcelain. Compare it to a new plug.
   Typical fix: Replace the spark plug in cylinder 3. It is highly recommended to replace all spark plugs at the same time for even performance. Ensure the new plug is gapped correctly.
   Est. part cost: $5-$25 per plug
2. Failing Ignition Coil 🔴 High Probability Ignition coils are subjected to high heat and vibration, leading to eventual failure. It's a very common failure point on modern coil-on-plug ignition systems like those in the Charger.
   How to confirm: The easiest method is to swap the ignition coil from cylinder 3 with an adjacent, easily accessible cylinder (e.g., cylinder 1 or 5). Clear the codes and drive the vehicle. If the code changes to the cylinder you moved the coil to (e.g., P0301 or P0305), the coil is bad.
   Typical fix: Replace the faulty ignition coil. Many owners choose to replace the corresponding spark plug at the same time.
   Est. part cost: $30-$90
3. Faulty Fuel Injector 🟡 Medium Probability Fuel injectors can become clogged with deposits over time or fail electrically, preventing the correct amount of fuel from being delivered to cylinder 3. Rodent damage to the injector wiring harness is also a known possibility.
   How to confirm: A mechanic can perform a fuel injector balance test. A DIY method involves listening to the injector with a mechanic's stethoscope to ensure it's clicking. Swapping injectors between cylinders is also possible but is more labor-intensive than swapping coils.
   Typical fix: Replace the fuel injector for cylinder 3. The fuel rail may need to be removed for access, and on the 3.6L V6, this requires removing the upper intake manifold. 🎬 Watch: Step-by-step spark plug and coil replacement for 3.6L V6.
   Est. part cost: $50-$150
4. Camshaft/Lifter Failure (Hemi V8 engines) ⚪ Low Probability The 5.7L and 6.4L Hemi engines have a known issue where a lifter's needle bearings can fail, causing the roller to seize and grind against the camshaft lobe. This results in a persistent misfire and a characteristic ticking noise ('Hemi tick'). This is often preceded by a P0303 code before escalating.
   How to confirm: This is a complex diagnosis. It often starts with a compression test. A visual inspection after removing the valve cover may reveal a worn camshaft lobe or a collapsed lifter. An owner on a Reddit forum with a P0303 and a tick on a 5.7L Pursuit immediately suspected this issue.
   Typical fix: Requires replacement of the camshaft, all lifters (especially on the affected bank), and related gaskets. This is a significant and costly repair, often costing thousands of dollars.
   Est. part cost: $800-$2000+

Rare But Worth Checking

• Intake Manifold Gasket Leak: A vacuum leak near the intake runner for cylinder 3 can lean out the air/fuel mixture and cause a misfire. This might be accompanied by a hissing sound or other vacuum leak codes. One owner found the previous owner had used RTV instead of proper gaskets, which could cause such a leak.
• Low Engine Compression: Caused by more severe issues like a leaking head gasket, worn piston rings, or a burnt valve. A compression test is needed to diagnose this.
• Rocker Arm/Lifter Issue (3.6L Pentastar V6): Some Pentastar engines can have issues with rocker arms or lifters that cause a ticking noise and misfire on cold starts. This has been the subject of class-action lawsuits, alleging premature wear of the rocker arm rollers. The fix involves replacing the affected rocker arms and lifters.
• Wiring Harness Damage: The wiring to the ignition coil or fuel injector for cylinder 3 can become damaged from heat, chafing, or even rodents chewing on the wires, causing an intermittent or constant misfire.

Diagnosis Steps

1. Retrieve the trouble code using an OBD-II scanner and confirm P0303 is present. 🎬 Watch this helpful guide on diagnosing and fixing P0303 codes. Note any other codes, like P0300, P0353, or P0203.
2. Identify cylinder 3. On the 3.6L V6, the cylinders are numbered 1-3-5 on the passenger side (front to back) and 2-4-6 on the driver's side. Cylinder 3 is the middle cylinder on the passenger side, under the intake manifold. On Hemi V8s, cylinders are 1-3-5-7 on the driver's side (front to back) and 2-4-6-8 on the passenger side. Cylinder 3 is the second cylinder back on the driver's side.
3. Swap the ignition coil from cylinder 3 with an adjacent cylinder (e.g., cylinder 1). Clear the codes, run the engine, and see if the misfire code moves to the new cylinder (P0301). If it does, the ignition coil is bad.
4. If the misfire remains on cylinder 3, inspect the spark plug. Remove it and check for wear, damage, or fouling. A cracked porcelain is a common culprit.
5. If the coil and plug are good, check the fuel injector. Listen for a steady clicking sound from the injector using a stethoscope or long screwdriver. Check the wiring harness for any visible damage.
6. If a ticking noise is present, especially on a Hemi, consider the possibility of a camshaft/lifter issue. A compression test is the next logical step. Low compression on cylinder 3 points to a mechanical problem.
🎬 See how to diagnose a flat camshaft on Hemi engines.
7. For 3.6L V6 engines with a cold-start tick and misfire, suspect a rocker arm or lifter issue. This requires removing the valve cover for visual inspection.
8. If compression is low, further investigation into the valvetrain (lifters, camshaft, rocker arms) or piston/rings is needed.

Parts You'll Likely Need

• Ignition Coil (OEM #68238603AA (For 5.7L/6.4L/6.2L Hemi, supersedes 68060346AA, 56029129AF)) — This is one of the most frequent causes of a single-cylinder misfire due to heat and electrical stress.
  Trusted brands: Mopar, NGK, Denso
  OEM price range: $50-$90
  Aftermarket price range: $30-$70
• Spark Plug (OEM #SP149125AF (For 3.6L V6), SPLZTR5A13 (For 5.7L Hemi), SP143877AA (For 6.4L Hemi)) — As a standard wear item, a worn or fouled spark plug is a primary cause of incomplete combustion and misfires.
  Trusted brands: NGK, Champion, Bosch
  OEM price range: $15-$30 per plug
  Aftermarket price range: $5-$20 per plug

Related Codes That Often Appear With This One

• P0300 — If the misfire is intermittent or affects other cylinders, a P0300 (Random/Multiple Cylinder Misfire) code may appear alongside P0303. This is common in the early stages of Hemi lifter failure.
• P0353 — This code indicates a malfunction in the ignition coil primary/secondary circuit for cylinder 3. If you see P0353 with P0303, it strongly points to a bad ignition coil or a wiring issue to the coil.
• P0203 — This code indicates a malfunction in the fuel injector circuit for cylinder 3. Seeing this with P0303 points directly to a problem with the injector itself or its wiring.

Technical Service Bulletins (TSBs) & Recalls

• TSB #18-094-16: This TSB involves a software update for the Powertrain Control Module (PCM) for various drivability improvements. While it lists P0303 among many other codes, it is not a direct fix for a specific mechanical failure causing the misfire. A PCM update is typically performed after mechanical causes have been ruled out.
• TSB #1400322REVA & #1809416: These TSBs list the entire family of misfire codes (P0300-P0308) as potentially related to the bulletin's subject, but they are not specific fixes for P0303 itself. The context is a broader software or system update where these codes might be present.

Platform-Specific Known Issues

• On 5.7L and 6.4L Hemi engines, a persistent P0303 code, especially when accompanied by a ticking sound, can be an early sign of camshaft and lifter failure, a well-documented issue with these powerplants. Owners on forums are often quick to suspect this when a simple coil and plug swap doesn't resolve the misfire.
• On 3.6L Pentastar engines, cylinder 3 is on the passenger side and requires removal of the upper intake manifold for access to the coil and plug, making the job more involved than for other cylinders.
• Later model 3.6L Pentastar engines (2016+) with Variable Valve Lift (VVL) can experience a unique failure of the intake rocker arm for cylinder #3, causing a cold-start misfire and ticking that subsides as the engine warms up. This has been the subject of a class-action lawsuit.

Hidden / Shadow Codes Worth Checking

• Mode 6, Test ID $53: This function within a generic OBD-II scanner can show misfire counts for each individual cylinder, even if a specific P030x code has not yet been triggered. It is useful for identifying low-level or intermittent misfires before they are severe enough to set a Check Engine Light. (see via A capable OBD-II scan tool with Mode 6 functionality. The data PID may be labeled 'Misfire counts for cylinder X' or similar.)

Scan Tool Commands That Help

• wiTECH: Monitors -> OBD II monitors -> 'Which cylinder is misfiring' — This function is used to view a live data block of misfire counts for all cylinders. It is particularly useful for diagnosing a P0300 (random misfire) to isolate the causal cylinder(s) or for confirming that the misfire is isolated to cylinder 3 when a P0303 is present.

Wiring & Ground Locations

• G306 — Right side of the engine compartment.. This is a ground point referenced in the electronic power steering system diagrams, but poor grounds in this area can affect various engine-related electronic systems, potentially contributing to sensor or actuator issues that could lead to a misfire code. Chrysler/Dodge vehicles ground many components directly to the engine block and chassis, making clean and secure grounds critical.
• Ignition Coil Control Circuit — Wiring from the PCM to the ignition coil for cylinder 3.. The PCM controls the ignition coil by switching the ground side of the circuit on and off to create a spark. A fault in this control wire (a short to ground or an open) will prevent the coil from firing and directly cause a P0303, even with a good coil and spark plug. This is often overlooked when basic component swaps fail.

Real Owner Repair Stories

• YouTube channel 'Fix It All' (Dodge Magnum 3.5L V6 (similar engine architecture and diagnosis to Charger)) — Misfire felt only when the engine was cold, confirmed P0303 with a scanner.
  ❌ Tried (didn't work) Initially suspected a wiring or coil pack issue.
  ✅ What actually fixed it After removing the upper intake manifold to access cylinder 3, the technician found the spark plug's porcelain insulator was cracked. Replacing the single broken spark plug resolved the cold misfire.
• Reddit user in r/Charger (2015 Dodge Charger Pursuit 5.7L Hemi, 106k miles) — P0303 and P0300 codes, rough cold start, slight shake at idle.
  ❌ Tried (didn't work) Swapped the two spark plugs for cylinder 3., Swapped the ignition coil for cylinder 3., Performed an oil change.
  ✅ What actually fixed it The issue was not resolved in the thread, but multiple experienced users immediately pointed to the common Hemi camshaft and lifter failure as the likely cause, especially given the high idle hours of a Pursuit model. The recommended next step was to cut open the oil filter to check for metal flakes, a tell-tale sign of internal engine damage.

OEM Part Supersession History

• 56029129AF, 68060346AA → 68238603AA — Standard part evolution for improved reliability or manufacturing changes.
  Heads up: The newer part number 68238603AA replaces the previous versions like 68060346AA and 56029129AF. They are interchangeable for this application.

Model Year Variations Within This Range

• 2016+: A PCM software update was released for 2016 models with the 3.6L engine to address several issues, including enhancements to the misfire monitor logic when a P0335 (Crankshaft Position Sensor Circuit) code is present. While not a direct cause of P0303, this indicates that software plays a role in how misfires are detected and reported, and ensuring the PCM has the latest software can be a valid diagnostic step.