The Cadillac CTS is a mid-sized car that replaced the Cadillac Catera in the 2003 model year. The CTS has a longitudinally-mounted V-6 engine at the front that drives the rear wheels. The original CTS 3.2-liter V-6 was enlarged to 3.6 liters for 2004 and had variable valve timing that helped boost its output to 255 horsepower. For CTS owners who perform their own routine maintenance, knowing where the air filter is located can help them save money by changing it on their own.
Park the car and turn off its ignition. Open and secure its hood.
Locate the air filter housing on the driver's side of the engine compartment, directly in front of the front wheel inner fender liner.
Remove the two retaining screws on each side of the air filter housing cover with a Phillips-head screwdriver.
Lift the cover straight up to reveal the air filter.
Replace the cover and tighten the retaining screws. Close the hood.
