Before and After - Tein S. Tech's

[Ben_]

Cold air intakes can be like the snake oil of performance modifications on some cars. These cars have 2 cats and a very restricting muffler. A full exhaust from the block to the rear bumper is going to make more power. Header 2" exhaust high flow cat and a straight through muffler will greatly increase efficiency of the exhaust stroke

[ern-diz]

Originally Posted by Ben_

Cold air intakes can be like the snake oil of performance modifications on some cars. These cars have 2 cats and a very restricting muffler. A full exhaust from the block to the rear bumper is going to make more power. Header 2" exhaust high flow cat and a straight through muffler will greatly increase efficiency of the exhaust stroke

Curious what the legalities are of both mods. I've read here on the forum that the CAI will typically be overlooked at the smog shop, but is easy to put back to stock to pass the test. Some folks report nice gains on the dyno too. Header back on the other hand might be a bit more trouble in the smog bay, no? I am in CA after all.