The largest online repair guide library for every car

About us
Contact support
FAQ
Sign up
Sign in

Rough Idle and Check Engine Light on 2020 Eclipse Cross (P0302)

0

Heather Y. · rep 0 · May 22, 5:36 AM · 1 replies · solved · Question

Vehicle: 2020 Mitsubishi Eclipse Cross SEL

Hi everyone,

I've been experiencing a rough idle and a persistent check engine light on my 2020 Mitsubishi Eclipse Cross SEL with about 45,000 miles. I hooked up my OBD-II scanner, and it's throwing a P0302 code, which indicates a misfire in cylinder 2.

The car feels a bit sluggish, especially at lower RPMs, and the idle is noticeably rougher than usual. I'm trying to figure out the most likely culprit. Could it be a bad spark plug, a faulty coil pack, or maybe even a fuel injector issue? Any advice on how to diagnose this further before I start throwing parts at it would be greatly appreciated!

✓ Accepted solution

ClearTheCode Admin

ClearTheCode Team · rep 0 · May 22, 5:36 AM

0

ClearTheCode admin answer:

  1. Understanding P0302: A P0302 code specifically means your engine's computer has detected a misfire in cylinder #2. This is a common diagnostic trouble code, and it points to an issue with the combustion process in that particular cylinder.

  2. Common Causes for Misfire (P0302):

    • Spark Plug: A worn, fouled, or incorrectly gapped spark plug is a very common cause.
    • Ignition Coil: A failing ignition coil for cylinder #2 can prevent the spark plug from firing correctly.
    • Fuel Injector: A clogged or faulty fuel injector might not be delivering enough fuel to cylinder #2.
    • Compression Issue: Less common, but low compression in cylinder #2 (due to valve issues, head gasket, or piston rings) can also cause a misfire.
    • Vacuum Leak: A vacuum leak near cylinder #2 could also contribute.

  3. Troubleshooting Steps (DIY):

    • Swap Spark Plugs: Start by swapping the spark plug from cylinder #2 with a known good cylinder (e.g., cylinder #1). Clear the code and drive. If the misfire moves to cylinder #1 (P0301), you've found your culprit: a bad spark plug.
    • Swap Ignition Coils: If swapping the spark plug doesn't change the code, swap the ignition coil from cylinder #2 with another cylinder. Clear the code and drive. If the misfire moves (e.g., to P0301), then the ignition coil is likely faulty.
    • Inspect Wiring: Visually inspect the wiring harness and connectors for the ignition coil and fuel injector on cylinder #2 for any damage or corrosion.

  4. When to See a Shop:

    • If swapping the spark plug and coil pack doesn't resolve the issue or move the code, the problem could be a faulty fuel injector. Testing fuel injectors often requires specialized equipment.
    • If the issue persists, a professional shop can perform a compression test on cylinder #2 to rule out internal engine problems. They can also check fuel pressure and injector pulse with diagnostic tools. Continuing to drive with a persistent misfire can damage your catalytic converter, so address it promptly.
Menu

Help & account