FYI for stalling in open loop and for PCM removal

The primary reasons for engine stall after warm up is the sensors trying to maintain stoichiometry (perfect fuel/air ratio). So always check to see if the air intake is compromised by a leak, dirty filters, dirty Mass Air Flow (MAF) sensor, throttle body and Manifold Absolute Pressure (MAP) sensor.
There are companies that will rebuild your PCM (aka ECM) for around $250. I found a good company in Houston Texas. However, when removing your PCM from the wiring harness connectors you will find that they are held by locking tabs that are quite flimsy and brittle. Before attempting to remove the connectors, clean them well with carb cleaner, brake cleaner, compressed air etc. then generously lubricate with WD40 or Liquid Wrench etc and slowly work the tabs lose. Do not force them. Also, if your PCM cannot be repaired a new DENSO for a Lexus will work for about $600. Either way will include your security codes so it is just plug and play. No code programming is necessary. This is for pre-2010 X100 and X150 XKs. I hope this helps someone.