I finally had the center muffler/axle/rear muffler/tail pipe replaced on my sister's '92 240 by my mechanic. Now that the job has been completed, everytime I start the car it sounds as if the exhaust is releasing a rather good size air bubble. Another way to describe the sound is as if the car is "burping." I have also noticed that after the exhaust was installed that as I come to a stop and shift(the automobile has a manual) from second into first, the car seems to "lurch" forward just a tad. Is it possible that I have an exhaust leak? Or is it possible that my mechanic installed the mufflers the wrong way(if that is even possible). Any insight would be greatly appreciated. Thank you :)