Why Doesn't a 2005 Chevy Malibu Have a Distributor Cap?by Kyle McBride
Chevrolet equipped your 2005 Malibu with either a 2.2-liter or a 3.5-liter engine. Both engines use a distributorless ignition system, eliminating the need for a distributor. Using input from various sensors monitoring speed and shaft positions, the powertain control module controls ignition timing, and the ignition coils deliver spark to the spark plugs.
Waste Spark Distribution
Your Malibu uses a waste spark distribution method. One coil delivers spark to a pair of cylinders simultaneously -- one cylinder on the compression stroke and the other on the exhaust stroke. The cylinder receiving the spark on the compression stroke is the cylinder that provides rotational power to the crankshaft. The spark delivered to the cylinder on the exhaust stroke is the "waste" spark, although it may serve to burn off residual hydrocarbons in the exhaust gas exiting the combustion chamber.