Exhaust leak
 

I have the stock manifolds and stock h pipe. Is it common to have an exhaust leak from where the manifolds connect to the the h pipe. I think I have a leak there because when the car is cold I hear a ticking from this area and when i shift i can hear a slight backfire from the area too. Could the exhaust leak cause the engine to backfire?
Thanks for any help

Yup, dude, thats probably the cause of your backfire. There's extra oxygen getting in there and ther unburnt fuel is igniting.

The flange separates all the time for me, especially after I went to aftermarket headers. The mac's had some cheap studs that came out the first time I tightened the nut and they have been backing off at regular intervals ever since. You'll need about 2 extensions at least to reach the nut down there and it's loads of knuckle busting fun! =P