I had the key for my car copied and didn't realize that it wasn't a microchipped key. My car was running perfectly. Then I tried to start the car with the new key. Started fine, stalled 3 seconds later. Did this twice, figured out the new key wasn't microchipped. Have been using my original key since. However, now my car won't accelerate, even on highways. Once up to running speed, it runs great, but it still sounds like it wants to sputter and it seems to sputter louder when idling. It doesn't stall, it just sputters. I don't know how to describe it, but when attempting to accelerate, it feels like the car can't breathe. Any ideas?