Well on the 23rd of Feb., a few days after my birthday, I was looking around magazines for a C4. I ran into one going for around 6k(pretty good) It's a 1992(first year for the Lt-1 motor). It's a beauty, some sort of blueish greenish color, I'd have to post some pictures soon(and it's in fair to good condition) but with the low pricing came the high mileage(nearing 150K). Anyways, I took it to the mechanic for the basics(New oil, oil filter, tranny fluid, fuel filter and differential) As I was driving down the expressway a rattle started(I was doing the speed limit(70)) It appeared to be coming from the exhaust. I also noticed my throttle response wasn't what it was early that day(at least it felt that way), in all rpm ranges, it just wasn't catching like it used to, if anything it's slacking. Could it be exhaust troubles chocking up my engine or what's the deal?? Another thing,maybe it's because the weather over here got warmer today but my oil and coolant temp. were rising to low 200's(214-222) where it would usually be around 184-201. Any answers or suggestions would be appreciated.(I plan on taking it back tomorrow morning to see what's the troubles) Thanks SVC.