hey guys I just got a used 08 Versa S sedan and its having problems starting in the cold...it seems like the throtle won't work or like it may be the fuel pump issue I have read about....its also got some smell of gas or exhaust fumes leaking into the car...I looked underneath the car to check the exhaust system and it is rusted pretty bad but I dont know much about cars why would I be smelling anything in the car??? How do I fix it for how much and how bad is it (both issues)