My '97 3.5L is giving me a migraine. It will start and idle just fine until; it warms up or I put it in gear, and once it's warm it'll start than immediately die. No codes from dash board or OBD II. Has anyone else had this problem?

 

check for vacuum leak under intake very common. with the engine running spray carb cleaner around the intake. if you hear engine speed change, you found the problem.