Did you replace the lock cylinder and key, or lock cylinder, key, and PassLock module?
Security codes are "B" codes, and most scanners can't read "B" codes....
If the car starts and dies, but will start by doing the 10 minute relearn procedure, you have a Security problem...
Who did the previous work?
If a new PassLock module was used, your problem could be the harness connection at the BCM.....
Keep a can of carb cleaner handy....when vehicle won't start, spray carb cleaner into the intake...then attempt to start....if it starts and runs until the carb cleaner is used up, it's a fuel delivery problem....check for fuel pressure, if ok, check for injector pulse.....if none, then I would suspect the Security system is shutting down the injectors....