ok, the shop told me i'm running rich. i have bbk long tubes, matching bbk h-pipe that he says doesn't exactly match right, and an sct 2. i have 60K miles, and have never changed the spark plugs. i bought a set of denso spark plugs, and haven't put them in yet. he says i'm running rich, i keep on having exhaust leaks, and my car just doesn't run like it has when i first put the long tubes on. could it be a combination of my bad spark plugs that i need to change and the leak? i can actually feel air coming out of the h-pipe where it meets the cat back system. someone also said something about checking my egr, maybe a fuel injector sticking, too much timing advance. someone please help! p.s. i know nothing about cars, keep it simple. haha