Start with cold air. If you can, do the exhaust at the same time. You can do the exhaust in two or three steps as well. ( Cat-back, then header/downpipe)
If you open it up to let it breath in, you need to let it breath out as well.
2007 LT 2.2
GMPP Air Intake * GMPP Extrude Honed Manifold * GMPP Cat-Back Performance Exhaust * Vibrant D/P * Jet Stage 2 Module
MOBIL 1 Synthetic Oil * DC Sport Strut Tower Brace * Color Matched Mirror Covers * EuroAntenna * 30-15 3M FX Tinting
Bridgestone Potenza Pole Position RE960AS on Premium Wheels
2.4 Intake Manifold Conversion * 2.4 TB * TUNE