Installing a cold air intake (CAI) on a Honda Civic is a popular upgrade for enthusiasts looking for more horsepower from their engine. The stock intake on a Civic is relatively restrictive while a cold air intake delivers additional cold, dense air to the motor for a power increase. The more cold air a Civic engine gets, the better it can run.
Open the hood. Remove the black plastic throttle body cover located between the top of the engine bay and the windshield with an 8 mm socket or a Phillips screwdriver. Remove the air filter under the cover.
Remove the mounting bolts for the baffle housing, which is just to the left of the top of the engine. Remove the bolts that hold the intake tube in place. There may also be a retaining clip that needs to be unclipped to remove the baffle housing. Remove the bolts that fasten the base for the filter housing to the intake manifold with a socket and ratchet.
Remove the hose that goes from the base of the filter housing to the engine as well as the temperature sensor located on the right side of the engine. Remove the reverse light switch with a 27 mm deep socket. Remove the ground cable and the clutch line bracket. Remove the two 12 mm bolts that hold the mounting bracket onto the transmission and remove the bracket. The cold air intake kit should come with a new, custom bracket.
Reinstall the reverse light switch. Install the new bracket where the old bracket was installed. Reinstall the ground cable. Install the rubber adapter sleeve onto the throttle body with the supplied hose clamp. Install the upper intake pipe onto the rubber adapter with a hose clamp. Install the support arm for the intake pipe onto the stock mounting point according to the directions.
Install the breather hose between the engine and the upper intake pipe. Install the intake sensor on the upper intake pipe. Attach the rubber adapter hose to the end of the upper intake pipe with a hose clamp, leaving it loose enough to move.
Mount the clutch line bracket that was removed in Step 3 onto the new bracket from the top, using the supplied bolt. Install the lower intake tube onto the adapter hose. Install the support arm onto the mounting bolt on the lower intake tube. Adjust the intake pipes and adapter hoses until they fit flush and are installed correctly. Tighten the hose clamps.
Raise the front end of the car with a floor jack and lower it onto a pair of jack stands. From underneath the car install the larger cone filter onto the end of the lower intake pipe with a hose clamp. Lower the car back onto the ground.
