I just installed C&L intake,JBA long tubes,catless mid pipe,and a flowmaster american thunder catback on a buddies car. He is currently in the marines and is getting stationed in California and I need to make it pass smog,any help would be great. Thanks.
If he's on active duty, he can keep his out of state tags (assuming it isn't already registered in CA). In most states, out of state registered vehicles aren't subject to local smog inspection. However in the communist state of Kalifornia, he may still be... in which case he'll have to remove the LTHs and mid-pipe and replace them with the stock units.
Penalties are so high for violating smog inspection procedures in Kalifornia I doubt he'd find anyone who will "pass" him with that exhaust configuration.
Most semi-custom tunes turn off the rear O2 sensors so that you can run an offroad x or h pipe. You will need to re-install the stock airbox, and return the tune to stock, in order to pass smog tests, otherwise you will have a "readiness failure" for the O2 sensors being ignored. I had this problem for the NYS inspections. I "detune" my car every year. Make sure you drive it about 100 miles after returning to the stock tune and before going in for the smog test. It's the only way to clear the readiness failures.