I haven't changed the plugs for nearly 5k miles maybe? But I have some new ones as I was going to wait till after Christmas to service the car, erm I have a resistor (tip121) I think it is? Because I see on the forum about changing it but I'm not confident with a soldering iron 😂 I can tig weld just not solder. As far as I'm aware there is no damage to any wires or any obvious faults