The largest online repair guide library for every car

About us
Contact support
FAQ
Sign up
Sign in

2018 Charger R/T Rough Idle and Misfire - P0301 Code

0

Jennifer H. · rep 0 · May 22, 5:41 AM · 1 replies · solved · Question

Vehicle: 2018 Dodge Charger R/T

Hey everyone,

I'm having some trouble with my 2018 Dodge Charger R/T, 5.7L HEMI. Lately, it's developed a really rough idle, especially when cold, and I can feel a distinct misfire. The check engine light came on, and when I scanned it, I got a P0301 code, indicating a misfire in cylinder 1.

The car has about 75,000 miles on it. I haven't done the spark plugs yet, but I'm wondering if it could be something else. Could it be an ignition coil, or maybe even a fuel injector issue? I've checked the oil recently, and it looks fine.

Has anyone else experienced this with their Charger? What steps did you take to diagnose and fix it? Any advice on where to start would be greatly appreciated before I start throwing parts at it.

✓ Accepted solution

ClearTheCode Admin

ClearTheCode Team · rep 0 · May 22, 5:41 AM

0

ClearTheCode admin answer:

A P0301 code specifically points to a misfire detected in cylinder 1. This is a common issue that can stem from several sources within the engine's ignition, fuel, or compression systems. Here's a breakdown of potential causes and diagnostic steps:

  1. Ignition System:

    • Spark Plug: A worn, fouled, or cracked spark plug in cylinder 1 is the most common culprit. They typically need replacement around 30,000-100,000 miles depending on the type. Given your mileage, this is a strong candidate.
    • Ignition Coil: The ignition coil for cylinder 1 could be failing. A failing coil won't deliver sufficient spark.
    • Spark Plug Wire (if applicable): While less common on modern HEMIs, a damaged wire could also be an issue.

  2. Fuel System:

    • Fuel Injector: A clogged, dirty, or failing fuel injector for cylinder 1 can prevent proper fuel delivery, leading to a misfire. You might notice a fuel smell or other related codes if it's severe.
    • Fuel Pressure: Low fuel pressure across the rail could affect all cylinders, but sometimes one cylinder shows symptoms first.

  3. Engine Mechanical (Compression):

    • Low Compression: Issues like a worn piston ring, damaged valve, or blown head gasket can cause low compression in cylinder 1, leading to a misfire. This is less common but more serious.

Diagnostic Steps:

  • Swap Components: A good first step is to swap the spark plug and then the ignition coil from cylinder 1 with a known good cylinder (e.g., cylinder 3 or 5). If the misfire code moves to the new cylinder, you've identified the faulty component.
  • Inspect Spark Plug: Visually inspect the spark plug from cylinder 1 for signs of fouling, wear, or damage.
  • Fuel Injector Test: A mechanic can perform a fuel injector balance test to check if the injector for cylinder 1 is delivering the correct amount of fuel.
  • Compression Test: If ignition and fuel systems check out, a compression test on cylinder 1 will determine if there's an internal engine issue.

When to See a Shop:

If swapping components doesn't resolve the issue, or if you suspect a fuel injector or compression problem, it's best to take your Charger to a qualified mechanic. They have specialized diagnostic tools to accurately pinpoint the problem without unnecessary parts replacement. Continuing to drive with a persistent misfire can lead to damage to your catalytic converter due to unburnt fuel entering the exhaust system.

Menu

Help & account