After running my engine for about 10 minutes and getting the engine to a temperature around 200 degrees f. my car starts to die and backfire until it finally just violently shuts off. I checked the fuel pressure while running and its fine so im guessing its something to do with the spark. Any thoughts?

 

The opti will sometimes act like that....so ill bad fuel and a dozen other things. Check the opti and do a CPM scan.

 

possible closed loop problem? o2's?

 

check the MAF. If scanned it should read 6gm/sec to 9gm/sec at idle and the numbers should increase rapidly when you accelerate. could also be dirty.