I have not seen a failed ignitor, but about 2000+ failed coils. drivers side, passenger side, either one can go. the reason is not clear yet I think its to do with the heat and locations they put them. could be a fualt with the ignitors over time but I doubt it. its almost always the coil or the rotor in the distributor going bad that leaves you with half the cylinders not firing.

 

My passenger side cap and rotor went bad causing half hot exhaust and half unburned fuel to be dumped into the cats making them red hot. Check your whole ignition system before buying parts you don't need, a new cap and rotor cost me 25 bucks (:

 

Yes the sc400 is notorious for failed coils, and the caps and rotors should be changed every 30-60k but for some reason people seem to think they will last 300k miles. the funny thing is they do last 150+k alot of times but usually the spark is much weaker on the worn out caps and rotors. I would replace them every 100k at the least.