Newbie Here in need of Maintence Help

[Tenspeed]

I have an 04 Mini Cooper S with 51k miles and was wondering what maintence should be done at what time. I have regularly changed my oil since I have owned the car at 22k miles and have changed the oil every 3k-5k miles, along with tire rotations every 5k-7k miles and I have always used 5w-40 full synthetic oil. About 2 months ago my exhaust rotted and fell off somehow so I had Meineke put a new one on for about $530+. Now they didn't put tips on the exhaust and it just has the straight pipes. There was a random misfire that occurred about 3 weeks ago, and acceleration since the exhaust has been put on just hasn't been the same. It lags a tad bit but overall still drives wonderfully. Any input would be very appreciated as all I want to do is love and care for this care to the fullest Thank you all for your time

[bad venge]

sounds like wrong backpressure causing performance issues

[Tenspeed]

Would this be caused by Meineke installing smaller than OEM or stock tailpipes? Being I have NEVER had this issue since before I went to them?

[bad venge]

It could be either too large or too small pipes or wrong mufflers ect

[Tenspeed]

I'm assuming so because what comes stock on the car I have read is supposed to be an exhaust with an inlet diameter of 2.25"...which I believe the pipes they installed (without any mufflers just a new resonator straight back with a y-pipe) are about 2" in diameter

[bad venge]

Wait you have NO MUFFLERS ? Thats the trouble

[Tenspeed]

When I first bought the car in Jan 09', I'm pretty sure it didn't have them then either. I brought it to this mechanic near me yesterday and said perhaps because it is supercharged it wouldn't need them? But I don't know much about cars but I thought that was a vital part to the exhaust system working correctly. I'm bringing it to a Euro mechanic this week and getting it evaluated since I Do not trust these so called mechanics at stores like Meineke or other places.

[Tenspeed]

While I am there I will try to get pictures of it and post them to see how ****ty the work has been done haha

[bad venge]

There are two "boxes" in the rear one is a resonator and the other is the muffler they are on either side of the rear bumper and the tips come out the center

[gijosh]

i have a 17% reduction supercharger pulley on an 06 R53. i need a smaller belt, but i dont know which belt, what size, where to get it. what have u. can anyone please help?