The Injen SP1579 SP Series cold air intake system for your 2012 Honda Civic SI 2.4 is the perfect upgrade to your vehicle. After removing your factory airbox, the Injen intake tube is directed directly behind the front bumper to acquire colder, direct air. The larger and cleanable Injen air filter then goes on the end of the intake tube. You wont ever have a check engine light because your mass air flow sensor bolts right up to the Injen intake on the Honda Civic. Injen dyno tuned this intake to ensure maximum horsepower and torque gains on your Civic while still maintaining proper air/fuel ratios. Depending on your driving habits, many users have also reported noticeable gains in fuel mileage, making the intake pay for itself over time!