P0302 on 2019-2023 Dodge Challenger: Cylinder 2 Misfire Causes and Fixes

What's Unique About the 2019-2023 Dodge CHALLENGER

The 2019-2023 Challenger offers a range of powerful engines, from the 3.6L Pentastar V6 to the 5.7L, 6.4L, and 6.2L Hemi V8s. While standard ignition issues are common across all engines, the V8s are known for a specific mechanical problem. A P0302 code on a Hemi can be a symptom of a failing valve lifter, often one of the MDS (Multi-Displacement System) lifters, which often creates an audible 'Hemi tick' and can lead to camshaft damage if not addressed. The 3.6L V6 has its own known issues with rocker arms that can fail due to bearing collapse, causing them to fall off and lead to similar misfire codes.

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
• Check engine light is on and may be flashing
• Fuel smell from the exhaust
• Reduced fuel economy
• Audible 'ticking' sound from the engine, especially when warm (Hemi V8s)

Most Likely Causes

1. Faulty Ignition Coil 🔴 High Probability → Shop Ignition Coil Coil-on-plug systems are common failure points due to constant heat and vibration. This is the most frequent cause for a single-cylinder misfire.
   How to confirm: Swap the ignition coil from cylinder 2 with another cylinder (e.g., cylinder 4). Clear the codes and drive. If the code changes to P0304, the coil is bad.
   Typical fix: Replace the faulty ignition coil. It's often recommended to replace the corresponding spark plug at the same time.
   Est. part cost: $30-$75
2. Worn or Fouled Spark Plug 🔴 High Probability → Shop Spark Plug Hemi V8 engines use two spark plugs per cylinder (16 total), increasing the probability of a single plug failing. They are a regular maintenance item that is often overlooked.
   How to confirm: After ruling out the coil, inspect the spark plug for wear, carbon fouling, or damage. You can also swap the plug with another cylinder to see if the misfire follows.
   Typical fix: Replace the spark plug in cylinder 2. It is best practice to replace all spark plugs if they are near the end of their service life.
   Est. part cost: $5-$25 per plug
3. Failed Valve Lifter / Camshaft Lobe (Hemi V8s) 🟡 Medium Probability → Shop Engine Camshaft The 5.7L and 6.4L Hemi engines are known for a 'Hemi tick' caused by the needle bearings in a valve lifter failing, often due to oil breakdown or extended idling. This is particularly common with the MDS lifters. This failure damages the camshaft lobe, leading to a persistent misfire.
   How to confirm: Listen for a distinct ticking sound from the engine when warm. A mechanic can perform a more in-depth diagnosis by removing the valve cover to inspect the lifters and camshaft lobes for wear or damage.
   Typical fix: This is a major repair that involves replacing the camshaft, all lifters (especially the failed one), head gaskets, and other related components. Many owners opt for an 'MDS delete kit' during this repair.
   Est. part cost: $800-$2000+
4. Faulty Fuel Injector ⚪ Low Probability → Shop Fuel Injector
   How to confirm: Listen to the injector with a mechanic's stethoscope to ensure it's clicking. You can also swap the injector with another cylinder, but this is more labor-intensive than a coil or plug swap, often requiring intake manifold removal.
   Typical fix: Replace the faulty fuel injector for cylinder 2.
   Est. part cost: $50-$150
5. Failed Rocker Arm (3.6L V6) ⚪ Low Probability → Shop Engine Rocker Arm The Pentastar V6 can suffer from rocker arm bearing failure, causing the arm to fall off or seize, which prevents the valves from opening and results in a misfire. A YouTube video shows this exact failure on a 2012 Challenger, where the mechanic finds missing rocker arms after removing the valve cover. 🎬 See this mechanic diagnose a V6 rocker arm failure
   How to confirm: After ruling out ignition and fuel issues, the valve cover must be removed to visually inspect the rocker arms and camshaft lobes for cylinder 2.
   Typical fix: Replace the failed rocker arm(s) and inspect the camshaft for damage. It's common to replace all rocker arms and lifters on that bank as a preventative measure.
   Est. part cost: $100-$300 for a set

Rare But Worth Checking

• Low Cylinder Compression: This indicates a more serious internal engine problem, such as a bad valve, worn piston rings, or a leaking head gasket. A compression test and a cylinder leak-down test are needed to confirm.
• Vacuum Leak: A vacuum leak isolated to the intake manifold runner for cylinder 2 could lean out the air/fuel mixture and cause a misfire. This is less common for a single-cylinder misfire code but can be checked with a smoke machine.
• PCM or Wiring Issue: In rare cases, a fault in the Powertrain Control Module (PCM) or a damaged wire in the harness to the coil or injector can cause the misfire. This should be considered a last resort after all other possibilities are exhausted.

Diagnosis Steps

1. Read the code with an OBD-II scanner to confirm P0302 is the primary code. Check freeze frame data to see the engine conditions (RPM, load, temperature) when the misfire occurred.
2. Locate cylinder 2. On Hemi V8s (5.7L, 6.4L, 6.2L), it's the front-most cylinder on the passenger side (right bank). On the 3.6L V6, it's the front-most cylinder on the driver's side (left bank).
3. Swap the ignition coil from cylinder 2 with an adjacent, easily accessible cylinder (like cylinder 4). Clear the codes and run the engine. If the misfire code moves to the new cylinder (P0304), the ignition coil is faulty.
4. If the code remains P0302, swap the spark plug from cylinder 2 with the one from the other cylinder. If the code moves, the spark plug was the issue. Inspect the old plug for fouling, oil, or damage.
5. If the misfire is still on cylinder 2, inspect the wiring and connector for the ignition coil and fuel injector for any damage, corrosion, or loose pins.
6. Listen to the fuel injector on cylinder 2 with a stethoscope; it should have a regular, audible clicking sound. Compare it to a neighboring injector.
7. For Hemi V8s, listen carefully for a 'ticking' noise when the engine is warm. A P0302 combined with a tick is a very strong indicator of lifter/camshaft failure.
8. If the above steps don't identify the problem, perform a cylinder compression test and a leak-down test. Low compression on cylinder 2 points to a mechanical issue (lifters, rocker arms, valves, piston rings).
9. For the 3.6L V6, if other tests are inconclusive, the next step is to remove the valve cover to inspect for a failed or dislodged rocker arm.

Parts You'll Likely Need

• Ignition Coil (OEM #68238603AA (replaces 56029129AF, 68060346AA)) — This is one of the most common failure items causing a single-cylinder misfire due to heat and vibration. This part fits Hemi engines.
  Trusted brands: Mopar, NGK, Delphi
  OEM price range: $50-$90
  Aftermarket price range: $30-$75
• Spark Plug (OEM #SP149212AC (6.4L Hemi), SP143877AB (5.7L Hemi)) — Spark plugs are a routine maintenance item. A worn, fouled, or damaged plug will cause a misfire. Hemi engines have 16 plugs, increasing the chance of failure.
  Trusted brands: NGK, Champion
  OEM price range: $15-$25
  Aftermarket price range: $5-$15
• Camshaft and Lifter Kit (Hemi V8) (OEM #53022263AF (Camshaft only, example)) — Required for the common 'Hemi tick' failure. The failed lifter damages the camshaft, necessitating the replacement of both. Kits often include gaskets, bolts, and non-MDS lifters.
  Trusted brands: Mopar, Cam Motion, COMP Cams
  OEM price range: $1000-$2000+
  Aftermarket price range: $700-$1500

Related Codes That Often Appear With This One

• P0300 — If the misfire is intermittent or affects other cylinders, a P0300 (Random/Multiple Cylinder Misfire) may be stored alongside P0302.

Technical Service Bulletins (TSBs) & Recalls

• TSB #18-035-26, #1400322REVA, #09-016-24: These TSBs are generic PCM flash updates that list P0302 among a wide range of misfire codes that the update may address. They do not point to a specific mechanical cause but are part of the diagnostic landscape.
• TSB #09-002-14 REV. B: While primarily for earlier 3.6L Pentastar engines (2011-2013), this TSB is highly relevant as it details the diagnosis and repair for the infamous left cylinder head failure that causes misfires on cylinders 2, 4, and 6.

Platform-Specific Known Issues

• Hemi Camshaft/Lifter Failure: On 5.7L and 6.4L Hemi engines, a ticking noise that accompanies a misfire code is a strong indicator of a collapsed lifter, which will in turn damage the camshaft lobe. This is a well-documented and serious issue requiring extensive engine repair. Forum threads on sites like RamForum.com contain owner stories of a P0302 code and ticking noise leading to a lifter and cam replacement diagnosis.
• Pentastar Rocker Arm Failure: The 3.6L V6 engine can experience failure of the rocker arms due to bearing collapse. This prevents the valves from operating, causing a misfire and often a ticking noise. A YouTube video of a 2012 Challenger with P0302 shows the mechanic discovering missing and broken rocker arms and a damaged camshaft lobe upon removing the valve cover.

Mechanic-Grade Diagnostic Values

• Fuel Injector Resistance (Hemi V8) — expected: Approximately 12.0 - 12.5 Ohms. Failure: A significantly higher reading or an open circuit (infinite resistance) indicates a failed injector.
• Ignition Coil Primary Resistance — expected: Approximately 0.46 Ohms. Failure: A reading outside of the specified range suggests a faulty coil.
• Fuel Pressure (All Engines) — expected: Approximately 58-60 PSI. Failure: Significantly lower pressure can cause a lean misfire.

Hidden / Shadow Codes Worth Checking

• P0352: Ignition Coil 'B' (Cylinder 2) Primary/Secondary Circuit Malfunction. This code is more specific than P0302 and directly points to an electrical fault with the ignition coil or its circuit, rather than just a general misfire. (see via This is a standard OBD-II code but may appear alongside P0302 on more advanced scan tools, helping to confirm the ignition coil as the root cause.)
• P0202: Injector Circuit/Open - Cylinder 2. This code indicates a problem with the fuel injector or its wiring for cylinder 2. (see via Like P0352, this is a standard OBD-II code that can be stored with P0302, narrowing the diagnosis down to the fuel injector circuit.)

Scan Tool Commands That Help

• wiTECH (or other advanced scanner): Cylinder Kill / Injector Kill Test — This function allows a technician to manually disable the fuel injector for cylinder 2. If the engine's idle quality does not change when cylinder 2 is disabled, it confirms that this cylinder was not contributing, verifying the misfire. Comparing the RPM drop to other cylinders helps gauge the severity.
• wiTECH (or other advanced scanner): Misfire Counter (Live Data) — Watching the live misfire data for cylinder 2 while driving under different conditions (idle, acceleration, cruise) can help determine when the misfire is occurring. A misfire only at idle might point to a vacuum leak, while a misfire under load is more typical of ignition or fuel delivery weakness.

Wiring & Ground Locations

• G904A — On the right side of the engine.. This is a key ground point for the engine control system. A loose or corroded connection at G904A could potentially cause erratic behavior in sensors or actuators, including the ignition coils or fuel injectors on the right bank (where cylinder 2 is located on V8s).
• Underhood Fuse Box / Power Distribution Center — Located in the engine compartment, typically on the passenger side.. This center houses the fuses and relays for the ASD (Auto Shutdown) relay, which powers the ignition coils and fuel injectors. A fault in this box, while unlikely to affect only one cylinder, is a critical point for power distribution to the entire ignition and fuel system.

Real Owner Repair Stories

• YouTube channel 'Sick Performance Shop' (2012 Dodge Challenger 3.6L V6) — Engine running rough, P0302 misfire code.
  ❌ Tried (didn't work) Swapping ignition coils between cylinders.
  ✅ What actually fixed it The mechanic removed the valve cover and found missing rocker arms and a damaged camshaft lobe for cylinder 2. The final repair involved replacing the camshaft, all rocker arms, and all lifters for that cylinder bank.
• ScannerDanner Forum (2014 Dodge Challenger 3.6L V6) — Constant P0302 misfire at idle and low RPM (<1500). No misfire at highway speed.
  ❌ Tried (didn't work) Swapping spark plugs, Swapping ignition coils, Swapping fuel injectors, Replacing the PCM (by a previous shop), Smoke test for vacuum leaks (passed), Cylinder leak-down test (passed), Replacing lifters and rocker arms for cylinder 2, Rebuilding the cylinder head (valves, guides, seats)
  ✅ What actually fixed it After extensive and costly diagnostics failed, the car was taken to a Dodge dealer who determined the cylinder head itself was faulty and required replacement. The final fix was replacing the entire cylinder head assembly.

When the Usual Fixes Don't Work

• While a P0302 code on a 3.6L V6 is often attributed to a simple ignition component or a known rocker arm failure, there are documented cases where the problem is far more severe. In one instance, after a shop replaced nearly every conceivable component including the PCM, lifters, and even had the head rebuilt, the misfire persisted. The ultimate resolution was a complete replacement of the cylinder head, as diagnosed by a dealership, indicating a difficult-to-detect flaw in the head casting itself. This serves as a caution against getting stuck in a loop of replacing common parts when the misfire does not resolve.

OEM Part Supersession History

• 56029129AA, 56029129AB, 56029129AF → 68060346AA, and most recently 68238603AA — Progressive design improvements for reliability and performance on Hemi engines.
  Heads up: While the latest part number (68238603AA) is generally backward compatible, it is highly recommended to use the newest available part number for replacement to benefit from the reliability updates. Avoid using older part numbers.

Model Year Variations Within This Range

• 2019-2023: While the core engines (3.6L V6, 5.7L, 6.4L, 6.2L V8s) remained largely the same through this period, minor revisions to software and emissions components occurred. The 'Last Call' models in 2023 marked the end of the V8 production for this generation but did not introduce fundamental changes that would alter the diagnosis of a P0302 code.