99 has ignition coil-on-plug, not plug wires.
The Catera 3.0L V6 is equipped with a distributorless ignition system. The system has 2 ignition coil packs. One coil pack is for bank 1 (cylinders 1, 3, and 5), and the other coil pack is for bank 2 (cylinders 2, 4, and 6). Each coil pack contains 3 coils, one for each cylinder on the bank. At the end of each coil is a boot, which connects directly to the spark plug. This eliminates the need for a spark plug wire, and the result is more precise ignition timing.
The engine control module (ECM) contains the ignition control module. The module precisely controls the ignition timing.
Friday, November 27th, 2009 AT 9:36 PM