The largest online repair guide library for every car

About us
Contact support
FAQ
Sign up
Sign in

2020 RDX Rough Idle and Misfire Codes P0301, P0303

0

Eric V. · rep 0 · May 22, 4:54 AM · 1 replies · solved · Question

Vehicle: 2020 Acura RDX A-Spec

My 2020 Acura RDX A-Spec, with about 60,000 miles, has recently started running really rough, especially at idle. The Check Engine Light came on, and when I pulled the codes, I got P0301 and P0303, indicating misfires on cylinders 1 and 3.

It feels like the engine is shaking more than usual, and sometimes there's a slight hesitation when accelerating. I haven't changed the spark plugs yet, as I thought they were good for longer. Could this just be spark plugs, or am I looking at something more serious like ignition coils or fuel injectors?

Any common issues with the 2.0T engine in the RDX that could cause this?

✓ Accepted solution

ClearTheCode Admin

ClearTheCode Team · rep 0 · May 22, 4:54 AM

0

ClearTheCode admin answer:

Rough idle and misfire codes (P0301, P0303) on your 2020 Acura RDX A-Spec are common symptoms that can stem from several sources. Given your mileage, it's a good time to investigate.

Here's a systematic approach to diagnose the issue:

  1. Spark Plugs: At 60,000 miles, spark plugs are a primary suspect. While some plugs are rated for longer, premature wear or fouling can occur. Start by inspecting and potentially replacing the spark plugs on cylinders 1 and 3. Ensure you use the correct OEM or equivalent iridium plugs.
  2. Ignition Coils: If new spark plugs don't resolve the issue, the ignition coils for cylinders 1 and 3 are the next likely culprits. You can swap the coils from the misfiring cylinders with coils from non-misfiring cylinders (e.g., swap coil 1 with coil 2). If the misfire code moves to cylinder 2 (P0302), you've identified a faulty coil.
  3. Fuel Injectors: Less common but still possible, a clogged or faulty fuel injector on cylinders 1 or 3 could cause a misfire. This can be harder to diagnose without specialized equipment. A fuel pressure test might be necessary, or a professional could test injector pulse and spray pattern.
  4. Compression Test: If spark and fuel delivery seem fine, a compression test on cylinders 1 and 3 can rule out internal engine issues like a bad valve or head gasket, though this is less likely at your mileage without other symptoms.
  5. Vacuum Leaks: A vacuum leak could cause a lean condition leading to misfires, but typically would affect multiple cylinders or cause a lean code (P0171/P0174) in addition to misfires.

When to See a Shop:

  • If swapping coils doesn't move the misfire, indicating the issue isn't the coil itself.
  • If you suspect fuel injector problems, as specialized tools are often needed for accurate diagnosis.
  • If a compression test is required, as this involves more advanced engine diagnostics.
  • If the issue persists after replacing spark plugs and testing coils, as it could point to more complex engine management or mechanical problems.
Menu

Help & account