99 cobra sputtering?
Man, I'll be honest. I've personally never come across those codes before. Only thing I can gather from that is the car is probably running pig rich. Why? I have no idea, but here's a free bump to your thread, hoping that someone can help you out.
Edit: Upon looking into your P0602 code some more, I found on various forums that your PCM could be corrupted and need to be reflashed. Not 100% sure on this, But It's a start. Certainly would explain your symptoms to a T, from what I've been reading.
Do you have an Aftermarket tune on your cobra? If So, try resetting it to stock and see what happens. If NOT, then I would take it to a trusted Ford dealership to have it reflashed.
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