Plugs were checked. One was replaced. Engine was tuned. It did not help. Oxygen sensors were replaced.
Problem is still here.
Wires were checked. No problem was found. The third cylinder is not firing, I replaced the spark plugs, and the third cylinder did not fire. The third wire did not give off a spark, so I replaced the spark plug wires, and still the third spark plug wire does not give a spark. My car has a distrributorless ignition system.