2 questions on the Ep3

Halllo, I bought my Ep3 today, 1.he was driven with 0W-40 oil, but now I have read here at some point that the oil even net is good for the ep3 engine and can possibly damage it, is that true or fake? 2. how much is an org. exhaust system worth for ep3 ?( nearly unused) Thanks for the help, mfG StevySg