21 challenger v6 with a missfire help only under 40,000km

Discussion in 'Challenger Mechanical Problems Forum | TSB's' started by toxicfire, Nov 21, 2025.

  1. Nov 21, 2025 at 3:40 PM #1
    toxicfire

    toxicfire Member

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    Hey Y'all. Yesterday, I noticed the car at idle felt like it had a misfire. I could feel it in the feet and steering wheel. Ran good otherwise- felt like same amount of power etc. Then, I guess, 2 hours later, after I park and the car's idling for 3 or 4 minutes, I hear a ding and engine light turns on.

    Still feels like a miss but not any worse, so we drive home- a 70-minute hwy drive- and I connect my dongle and run a scan.

    P0302 cylinder 2 misfire.

    Take to shop today and he said it needed a spark plug in cylinder 2. So, he changed all the plugs since he had the intake manifold off. Says it's not showing any more misses.

    EDIT! So, 20-minute hwy drive home and pull into town, the car is running like yesterday and I can feel the miss and then the engine light turned on again and same thing miss on cylinder 2.

    Shop is saying it has to be an injector because coils and new plugs.

    Any insight or opinions would be nice.
     
  2. Nov 21, 2025 at 3:56 PM #2
    SRT-Tom

    SRT-Tom Well-Known Member Staff Member Super Moderator Article Writer

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    Conditions which promote the storage of a P0302 are likely to cause catalytic converter and/or engine damage. This severe code should be addressed immediately.

    An OBD II code P0302 is usually caused by a lack of a high intensity spark. However, it may have been triggered by many things, besides bad spark plugs, such as: defective ignition coil(s), bad spark plug boots, faulty fuel injector(s), malfunctioning fuel delivery system (fuel pump, fuel pump relay, fuel injectors, or fuel filter), major engine vacuum leak, EGR valve stuck in the wide open position or clogged EGR ports.

    Read the following to help diagnose and repair the misfire.

    https://www.obd-codes.com/p0302
     
    Last edited: Nov 21, 2025
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  3. Nov 22, 2025 at 12:44 AM #3
    Cloverdale

    Cloverdale Full Access Member

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    Yours is that terrible design that requires the intake removal to access coils, plugs and injectors (by design for dealership servicing / labor billing purposes post warranty?). You shared only the plugs had been changed (coils as well?). On many engine designs with easier access one can first swap the suspect coil with another cylinder coil and and see if the misfire follows to that cylinder. If it doesn't then do the same swap of the cylinder injector. In your case that approach is not practical due to the required intake re and re. A removed coil and injector can be bench tested. Seems your shop didn't do that which might have saved all the inconvenience and cost of revisiting your misfire.
     
    Last edited: Nov 22, 2025
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  4. Nov 22, 2025 at 11:26 AM #4
    HellKitten

    HellKitten Full Access Member

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    Whoever you took it to for servicing should have been able to diagnose the problem. Also with the milage on this car and being a 2021 model you should be under warranty 5years or 60K. Call a local Dodge dealer and ask.

    If for some reason it's not under warranty, I would gamble and replace the coil and injector for that code.
     
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  5. Nov 24, 2025 at 10:35 AM #5
    Hemi59

    Hemi59 Member

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    Most likely by your description it's the coil. There are some great videos out there if your a diy person.