Coil-on plug was not terribly common in the 90's. More likely you would have had a "distributorless" ignition system with a coil pack mounted somewhere in the engine compartment and plug wires from that to the engine. Earlier in the 90's you would have still had a distributor but with electronic fuel injection either by direct injection or by throttle-body injection. The only TBI engine I've had was an OBD1 system with a distributor attached to the oil pump. It was built in 1995. The only electronic ignition engine I drove from the 90's was from 1996 and it had an OBD2 system with a coil pack. My first coil-on-plug engine was from 2006.

Otherwise this is a great article.