2018 CX-5 Check Engine Light - P0301 Misfire on Cylinder 1

ClearTheCode guidance (Mazda · Diagnostics & codes)

Summary: For 2018 CX-5 Check Engine Light - P0301 Misfire on Cylinder 1, work through these steps on your 2015+ vehicle:

1. Confirm the symptom — note when it happens (cold start, highway, after fuel fill, etc.).
2. Scan codes — save all pending/stored DTCs; don't clear until you've recorded them.
3. Check TSBs & recalls — look up your VIN for open campaigns and known fixes.
4. Inspect the obvious — related fuses, connectors, fluid level, and recent repairs.
5. Test the common fix — follow model-specific service procedures; one change at a time.
6. Escalate if needed — burning smell, no brakes, overheating, or stalling in traffic → shop visit.

Owner reported: Hey everyone,

My 2018 Mazda CX-5 Grand Touring (2.5L engine) just threw a Check Engine Light. I noticed a slight rough idle and a bit of hesitation when accelerating, especially at lower speeds. I pulled the code with my OBD-II scanner, and it's showing P0301, which indicates a misfire on cylinder 1.

What are the common causes for this on these CX-5s? I've heard it could be spark plugs, ignition…

This is educational guidance, not a substitute for hands-on diagnosis.