or maybe its the muffler. Basically, I was going along, and put it into gear, and suddenly, the engine got really, really loud, and it was sputtering and shaking and all sorts of bad stuff. Its a 98 Legacy GT sedan, with the 2.5 swaped out for a 2.2(which is much more reliable ive been lead to believe). What do you think it could be and how much do you think its gonna cost? I'm scared.