Your 2022 Elantra's steady check engine light with P0302 points directly to cylinder 2—it's misfiring while the other cylinders work properly. This focused diagnosis lets us investigate cylinder 2's spark, fuel, and compression to find the culprit.
What P0302 Tells Us
The P0302 code indicates "Cylinder 2 Misfire Detected." The engine computer tracks combustion events in each cylinder through crankshaft position sensor data. When cylinder 2 isn't contributing its power stroke properly, the computer flags it specifically.
Symptoms You're Experiencing
- Steady check engine light (flashing if severe)
- Engine vibration or roughness
- Loss of power
- Possible stumbling during acceleration
- Decreased fuel economy
Finding Cylinder 2
On the 2022 Elantra's 2.0L Smartstream engine, cylinders are numbered 1-4 front to back. Cylinder 2 is the second from the front (toward the firewall side of the engine).
Common Causes
- Failed ignition coil: Coil-on-plug not producing spark
- Worn spark plug: Bad plug in cylinder 2
- Fuel injector issue: Clogged or stuck injector
- Vacuum leak at cylinder 2: Intake gasket or runner issue
- Low compression: Valve or piston ring issue
The Swap Test
This is the fastest way to diagnose ignition-related misfires:
- Swap cylinder 2's ignition coil with cylinder 1
- Clear the code
- Run the engine until the light returns
- If the code changes to P0301, the coil was bad
- If P0302 remains, swap spark plugs next
Diagnostic Approach
- Perform the coil swap test
- Inspect cylinder 2 spark plug condition
- Check fuel injector operation with stethoscope
- Look for vacuum leaks near cylinder 2 intake runner
- If ignition and fuel check out, perform compression test
Repair Costs
- Ignition coil: $75-$175
- Spark plugs (set of 4): $100-$200
- Fuel injector: $150-$350
- Injector cleaning service: $100-$200
- Compression-related repair: $1,000+
Your 2022 Elantra is under Hyundai's 5-year/60,000-mile powertrain warranty—have the dealer diagnose it.