Q: where is the ecm located in my 2001 lesabre and how do I get the part number off of it

Hello - to answer your location question, the ECM is behind the fuse and relay block of electronics under the passenger side of the dash (behind the glove box). The ECM is behind the other electronics, mounted flat against the firewall, and is an aluminum box about the size of a good hardbound book. The part number should be on a decal on the outside of the ECM. As for you stalling, several problems could cause this. These include a dirty or failed idle air controller, an air leak to the intake system, a dirty throttle body, an EGR valve stick (even slightly) open. What problem codes are still present causing the Check Engine light to illuminate? These should be helpful. I would recommend having a Car Is Stalling Inspection completed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.