Navara came into the workshop with an engine that idles roughly and when you accelerate the engine jerks. I do suspect the ignition coils, a diagnostic test shows nothing. I pull out the coils and test them with a coil tester. All six were apparently cracked just below the coil itself. The coils work perfectly but because of these tiny cracks, the spark will jump out to the metal side of the engine. The spark plugs are fitted deep into the cylinder head so the spark has to travel down to the plug. If this happens to your car coils you can use a rubber pipe, cut short peace, and pull them over the bottom part of the coil to insulate the coil’s barrel/tube as far as possible.
See the video below, this tip work quite good, the coils might be working perfectly for a long time
Must say in the end it is better to replace all the coils with new ones.