Its alot cheaper to order everything online, i order every part online, i normally save 50%-70% off what the local part shops cost. Thats me though. The cat converter is easy, its 4 bolts, you just have to be carefull not to break the bolts, the two on the engine block on mine came off like butter with my impact gun and the right extensions, the two underneath by the resonator broke on me, and i had to drill them out.