Something may have chewed into some electrical wires... which could be very easy to find, or one huge massive PITA. Obviously it is getting some massive amount of current, which isn't good for other systems also. Does he have the wrong fuse in for that circuit???? I'd rather blow fuses than coil packs, especially while troubleshooting, duh!
Other than that, if it's the EJ25D there are head gasket problems pretty much guaranteed 130-180K miles. I'd want compression and leakdown results from any EJ25D, it is so easy to do anyways.