Ok .. I don't know what a CAI is ... I'm just asking this for a friend because neither of us know ... So, if you take a standard setup for a cold air intake, note just a standard, stereo-typical setup, could the OEM filter stay where it is and the cold air intake is added on and works in conjunction with it, or does the OEM air filter and housing for it come off and only the cold air instake is used ... ??? Thank you!
You can do both, but using the stock airbox with a CAI defeats the purpose of doing it in the first place. The correct way is to take out the airbox and associated intake parts all the way to the throttle body. Then you connect the CAI directly to the throttle body, and put a cone filter on the end, which is located somewhere down in the fender. If you get the correct CAI, the airflow sensor and EGR tubes will connect directly to the new CAI pipe. Check out this link for more info http://en.wikipedia.org/wiki/Cold_air_intake