Was out with it yesterday and it was running perfect until I heard a twang from under the hood and then a rattle. After that, whenever I let off the throttle it wanted to die. I managed to get it back to the truck and as soon as I let go of the throttle it quit and I wasn't able to get it to start again. I lifted the hood and found that the exhast can had separated from the manifold due to a broken spring retainer and I'm really hoping thats all the problem is. Is it possibel that an exhaust leak could cause the low idle and not starting issues?