My sister has a 95 esi and the exghuast (a few feet after the cat) is rattling like crazt when you move through the rpm's once you stay at the same speed it stops, Also her car is pretty damned slow, even compaired to what it used to be at 50k miles. She has 75 now I was wondering if you are supose to replace the plugs and wires at 60,000 or what. Also about the rattling could it be the cat is clouged? Thats what I thoght it might be after drving it, also her friend and my brother both came up with the same thing on their own. (kinda wierd) Or could the rattling be from a bushing that is missing or has worn off? And how would the car sound with no cat and stock exghuast?