Do muffler muffler delete axle back exhausts harm the engine?

Originally Posted by 370zsport

Thanks for all the replies. I feel better about it now. Especially since I got input from the company I bought them from. So thank you. Im not used to a forum where people who work for a company actually chime in and give advice/help so its refreshing to see this. Thanks AAM for the reply along with everyone else whos given advice. As for my car, yes there were a bunch of problems but considering where I bought the car from, Im not surprised(its my fault for thinking they would be honest after what had happened with the 350z I had purchased a day before that, which ended up being bought back by them in exchange for this car because I was so angry and had so many issues after only having it 3 days). I just figured a car with only 20k miles, wouldn't have as many problems as I have had so far.(I was wrong) Funny thing is even with the new transmission and the new throwout bearing and new GTR clutch fluid being replaced, and having them rebleed it again for piece of mind and having the tech test drive it with me and fixing some TSB's, it still has the same sounds coming from the trans(little bearing noise probably from the design of the throwout bearing) along with notchy shifts. My only thought is that maybe since it a completely new transmission, new fluid, that maybe it needs a break in period before these issues correct themselves a little bit and don't make a millisecond grind in each gear. Its drivable, but until the car warms up a good bit, the shifts in 1st to 2nd, and 2nd to 3rd are notchy and almost sound as if they are slightly grinding before going in. Ive never had a 370z or a 350z for that matter, always had integras and civics and mustangs etc, so maybe what I am hearing and feeling after a complete replacement is simply how its designed. Maybe they are just noisey and are notchy. I dunno. Thanks for everyones input!