hey question, i just bought an 04 WRX with 85,000 miles on it about 3 months ago, and i noticed it doesnt idle as smooth as it should, a mechanic said it could be fixed just by a tune up? but one how much does a tune up cost, my car is 100 percent stock, and any ideas of where to go other then a dealer in salt lake? dealers just like to bend you over and take all your money! and is this something i could fix myself?