so im driving to get pizza and the car is running great.... i tell my gf how good its running and im all happy. i get to the pizza place sit down eat....... get back in my car and start driving..... i used to live by this road that was long wit nobody on it so i could go fast so i figure ill do it tonight...... the car is running fine till i get like 5 mins from the road ... i get on it a lil and i hear a gargle type niose coming from the exhaust almost like a down shift but a lil louder....... so now im like wtf... i get on it again and it happens agaion.. i first thought it was my spare tire rattaling around but then i got on it hard and it made the noise but didnt go away till i let off... and then the ses light came on...ne ideas on what that could be?????? i w as able to make it home and it doesnt happen if i dont get on it