The cat is brand new, magnaflow high flow. The exhaust is changed from the cat back with 2.25 and a magnaflow muffler. It sounds really good. My car is a 190e 2.6 auto. I thought it was the exhaust before but there is no way it could rattle. It is no where near the body. The speedo cable idk about that. The speedo jumps up and down in the cold but that's it. No weird noises from that. It sounds like it's coming from the tranny but I can't tell. My girlfriend and my brother are deaf it seams like lol. They don't hear it. That's why I thought it was my driveshaft.