Master Muffler has gone far and above my expectations with working on my engine. I had no idea what was wrong with my car when I took it in but they were able to pin point the problem to the engine. I took my car in the next day to get it fixed because I didn't have the time that day to have them continue work on it. I dropped it off and got back a few hours later and it was just fine. I haven't had any problems with it and don't anticipate any other problems.