2023 Dodge Charger Misfire? Here's How to Fix It (Intake Leak)

Understanding the Problem

A misfire occurs when one or more of an engine's cylinders fail to ignite the air-fuel mixture properly. This disruption in the combustion sequence leads to a loss of power, rough running, and increased emissions. While the symptom is straightforward—the engine stumbles or shakes—the root cause can stem from a wide variety of issues within the ignition, fuel, or mechanical systems. Diagnosing a misfire is a process of elimination, often starting with the simplest and most common components before moving to more complex and expensive possibilities.

From the Community

Analysis of 100 owner discussions reveals that misfire experiences vary widely, but common threads emerge. Many owners first notice the problem under specific conditions, such as during cold starts, under heavy acceleration, or when the engine is under load (like climbing a hill). A frequent point of consensus is the importance of retrieving diagnostic trouble codes (DTCs) from the vehicle's OBD-II system, even though specific codes were not highlighted in this dataset. Community members strongly advise against simply replacing parts at random, emphasizing that a systematic approach saves both time and money. Discussions also occasionally branch into vehicle modifications (like wide-body kits or performance gearboxes), but these are generally treated as separate topics from solving a core mechanical misfire issue.

Common Indicators

Owners describing a misfire report several key sensations and observations:

• Check Engine Light (CEL): The most universal indicator, often flashing during an active misfire to warn of potential catalytic converter damage.
• Rough Idle: The engine shakes or vibrates noticeably when the vehicle is stopped, feeling uneven and lumpy.
• Loss of Power and Hesitation: The vehicle feels sluggish, especially during acceleration, and may stumble or buck.
• Audible Changes: The exhaust note may become irregular, popping, or sputtering. The engine itself may sound uneven.
• Increased Vibration: The shaking from the rough idle often translates through the steering wheel, floor, and seats.

Likely Culprits

Based on patterns in owner reports and standard automotive repair knowledge, misfires typically originate from one of three systems. The likelihood generally descends in this order:

1. Ignition System (Most Common): This includes faulty spark plugs, failing ignition coils or coil packs, and damaged spark plug wires or boot. A weak or absent spark cannot ignite the fuel.
2. Fuel System: Problems here involve clogged or leaking fuel injectors that deliver too little or too much fuel, or a weak fuel pump that fails to provide adequate pressure.
3. Engine Mechanical Issues (Less Common but Serious): This includes low compression due to worn piston rings, leaking valves, or a failed head gasket. It can also involve issues with variable valve timing systems or, in rare cases, problems with the engine control module (ECM) itself.

What Works

The following solutions are ranked from the most frequent/least costly to the least frequent/most involved. Always start with retrieving OBD-II codes to guide your diagnosis.

1. Scan for Codes & Basic Inspection (First Step for All) Before any parts are replaced, plug in an OBD-II scanner. A code like P0301 indicates a misfire in cylinder #1, which directs your efforts. Visually inspect for obvious issues: cracked vacuum hoses, disconnected wiring, or damaged spark plug boots.

2. Ignition System Service (Top Fix) This is the most common and successful starting point.

• Replace Spark Plugs: Worn or fouled plugs are a prime culprit. Use the type and gap specified for your vehicle.
• Replace Ignition Coils/Coil Packs: Coils often fail with heat and age. A common and effective diagnostic trick is to swap the coil from the misfiring cylinder with one from a healthy cylinder. If the misfire code moves, you've found the bad coil.
• Cost Range: $50 - $300 for parts, depending on the number of cylinders and coil type.

3. Fuel System Cleaning/Service If ignition components check out, fuel delivery is the next suspect.

• Clean Fuel Injectors: Use a reputable fuel injector cleaner additive or have a professional cleaning service performed.
• Replace Fuel Injector: If cleaning doesn't resolve a consistent misfire on one cylinder, the injector itself may be faulty.
• Cost Range: $20 (additive) to $150 (professional clean) to $300+ per injector.

4. Mechanical Diagnostics (Professional Help Recommended) When ignition and fuel are ruled out, mechanical testing is required.

• Compression Test: Measures the engine's ability to build pressure in each cylinder. Low compression points to internal wear.
• Leak-Down Test: Pinpoints the source of low compression (rings, valves, head gasket).
• Cost Range: $150 - $300 for professional diagnosis. Repairs like valve work or head gasket replacement can cost $1,000+.

DIY vs Shop Costs

The cost to fix a misfire is highly dependent on the root cause.

• DIY Approach:

  • Parts-Only Cost: $50 - $600.
  • Scenario 1 (Spark Plugs): A set of plugs costs $25-$100. Difficulty: Easy to Moderate.
  • Scenario 2 (One Ignition Coil): $50-$150 for the part. Difficulty: Easy (if easily accessible).
  • Scenario 3 (Fuel Injector): $100-$300 per injector. Difficulty: Moderate to Hard, often requiring intake manifold removal.
  • Pros: Significant cost savings on labor. Cons: Requires tools, time, and diagnostic skill. Risk of misdiagnosis.

• Professional Shop Approach:

  • Parts & Labor Cost: $200 - $2,000+.
  • Diagnostic Fee: Typically $100 - $200.
  • Typical Ignition Job (plugs & coils): $400 - $800.
  • Fuel Injector Replacement: $500 - $1,000 for one.
  • Major Mechanical Repair (head gasket, valves): $1,500 - $3,000+.
  • Pros: Expert diagnosis, warranty on work, no tool investment. Cons: Higher overall cost.

Questions & Answers

Q: Can I drive with a misfire? A: It is strongly discouraged. A flashing Check Engine Light means an active misfire that can quickly overheat and destroy the expensive catalytic converter. Even with a steady light, driving can lead to further damage, reduced fuel economy, and failed emissions tests.

Q: I replaced all my coils and plugs, but the misfire remains. What now? A: This indicates the problem lies elsewhere. The next steps are to check fuel delivery (injectors, pressure) and then perform a compression test to rule out mechanical engine problems. A professional diagnosis is highly recommended at this stage.

Q: Why does my misfire only happen when the engine is cold or when accelerating? A: Cold misfires often point to fuel delivery issues (a leaking injector flooding the cylinder) or a worn spark plug with a too-wide gap. Misfires under load (acceleration) are classic symptoms of a weak ignition coil or a clogged fuel injector that can't meet demand.

Q: Are misfire fixes always expensive? A: Not at all. Many misfires are solved with sub-$200 in parts (plugs and one coil) if diagnosed correctly. The key is to follow a logical diagnostic process rather than guessing.

Source Summary: This analysis is based on 100 owner discussions from Reddit and automotive forums.