You'll pass emissions with a header. Hell, you can pass with no cats on '02-'03 so long as you fool the ECU. '04 + won't communicate with the current emissions software in GA, so if the state dosn't update soon '04's will get a 2 speed idle sniffer test. Focus', mazda's, maxiams, and other CAN equipped cars are going to get a sniffer test in 2007 untill the software is updated.