CAI for 08 impala ss
http://www.knfilters.com/search/prod...x?Prod=63-3059
While K&N does not list the 2008 Impala SS as an application, the dyno sheet for this kit says it was in a 2006 Impala SS.
I highly doubt there were significant engine bay layout changes between those years.
I would order it through your local auto parts store. I would say it is a 99% chance it will work with no problem. If it doesn't for some odd reason, return it.
http://www.wundercarparts.com/search...FQIWFQod8lGGEg


