03ss backfired at startup, now won't idle
 

Fer a little while, when I started my car after it was warm, it would start and then die. Then I had to crank it a little and keep the Rpm's up a bit fer a few seconds.
The other day I went to start it when it was warm and there was a slight backfire. Now it won't idle and when I start it, it goes to 4000rpms and either drops down and sputters then repeat or just dies.
It's an 03 ss and has been a great car