Diagnostic manual index

obd2.help
AboutEspañol
OBD2.help›Powertrain›P0302

P0302

Cylinder 2 Misfire Detected

Your engine's cylinder 2 is not firing properly. This means the fuel-air mixture in that cylinder is not igniting correctly, causing the engine to run rough and lose power.

SEV
3/5
DRIVE
CAUTION
DIY
$20–$200
SHOP
$150–$600

Quick answer

AI-CITATION READY

What it means

The PCM has detected that cylinder 2 is misfiring based on crankshaft position sensor data showing irregular rotation. The misfire rate has exceeded the manufacturer's threshold for triggering a diagnostic trouble code. This can be caused by ignition, fuel delivery, or mechanical issues specific to cylinder 2.

Can you drive with it?

With caution. You can drive short distances at low speeds, but prolonged driving risks catalytic converter damage and increased emissions.

Most common causes

  • Worn or fouled spark plug in cylinder 2
  • Faulty ignition coil on cylinder 2
  • Damaged or worn spark plug wire/boot

Typical repair cost

DIY usually runs $20–$200. Typical shop repair lands around $150–$600, depending on the root cause.

01 / Definition

The PCM has detected that cylinder 2 is misfiring based on crankshaft position sensor data showing irregular rotation. The misfire rate has exceeded the manufacturer's threshold for triggering a diagnostic trouble code. This can be caused by ignition, fuel delivery, or mechanical issues specific to cylinder 2.

02 / Drive status

With caution. You can drive short distances at low speeds, but prolonged driving risks catalytic converter damage and increased emissions.

03 / Symptoms

  • Rough idle or engine vibration
  • Check Engine Light flashing or steady
  • Loss of power during acceleration
  • Engine hesitation or stumbling
  • Increased fuel consumption
  • Raw fuel smell from exhaust

04 / Causes

1Worn or fouled spark plug in cylinder 2high
2Faulty ignition coil on cylinder 2high
3Damaged or worn spark plug wire/bootmedium
4Clogged or failing fuel injector on cylinder 2medium
5Vacuum leak near cylinder 2 intakemedium
6Low compression in cylinder 2 (worn valve or piston ring)low

05 / Diagnostic sequence

  1. 01Read freeze frame data to identify conditions when misfire occurred
  2. 02Inspect spark plug on cylinder 2 for wear, fouling, or damage
  3. 03Check ignition coil on cylinder 2; swap with another cylinder to confirm
  4. 04Test fuel injector on cylinder 2 for proper operation
  5. 05Perform a compression test on cylinder 2
  6. 06Check for vacuum leaks around the intake manifold near cylinder 2

06 / Repairs

1Replace spark plug on cylinder 2$5–$25
2Replace ignition coil on cylinder 2$30–$100
3Replace spark plug wire or boot if applicable$20–$60
4Clean or replace fuel injector on cylinder 2$50–$200
5Repair vacuum leak if found$20–$150

MFG / Manufacturer notes

These supplements add make-specific diagnostic framing. Pages without full matrix backing or lane approval stay guarded and canonicalize back here until they are explicitly approved for indexing.

  • Audi P0302

    Approved indexable child page

    Open

07 / Related codes

  • P0300
  • P0301
  • P0303
  • P0304
  • P0305
  • P0306

08 / FAQ

Can a misfire damage my catalytic converter?

Yes. Unburned fuel from a misfiring cylinder enters the exhaust and can overheat and damage the catalytic converter if not addressed promptly.

Why is only cylinder 2 misfiring?

Single-cylinder misfires usually point to a component specific to that cylinder, such as its spark plug, ignition coil, or fuel injector.

Should I replace all spark plugs if only one is bad?

It is generally recommended to replace all spark plugs at the same time, as they wear at similar rates and replacing all ensures consistent performance.

09 / Source and method

DATA BASIS
OBD-II REFERENCE + OBD2.HELP
METHOD
STATIC VALIDATION
SAFETY
INFORMATIONAL

This page combines OBD-II diagnostic reference data with OBD2.help generated diagnostic guidance for code meaning, likely causes, and repair direction.

Publishing uses deterministic schema and build validation, plus manual spot checks on representative pages before release.

Safety-critical diagnosis and repairs should be confirmed with a qualified mechanic, especially when the vehicle is misfiring, overheating, or losing power.