Cylinder 4 Misfire Detected

What it means

Cylinder 4 is not contributing its full power because ignition there is incomplete. The fault is usually the coil, spark plug or injector, and only rarely inside the engine.

Symptoms4

• Engine shake that gets worse with the air conditioning on at a standstill.
• Weakness and stumbling on acceleration.
• Check engine light on or flashing.
• Fuel smell from the exhaust.

Possible causes6

• Damaged or arcing ignition coil on cylinder 4.
• Old or broken spark plug in cylinder 4.
• Clogged injector on cylinder 4.
• Damaged connector or wiring for the cylinder.
• Vacuum leak at the cylinder intake.
• Low compression (less common).

How to diagnose and fix5

1. Swap the cylinder 4 coil with another cylinder and watch whether the code follows.
2. Inspect the spark plug and replace it if worn.
3. Check the injector and connector; clean or replace it.
4. Inspect vacuum hoses near the cylinder.
5. Request a compression test if the misfire stays on the same cylinder.

Repair cost

In Saudi riyals; the highlighted part is the expected range for this fault.

The fix is usually a single low-cost part, with higher costs only if an internal mechanical fault is found.

Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.

Frequently asked questions