great you get a report also!, here there is nothing I must say that the quality of repair done in USA is no match what is done here, although expensive but its worth it
Have you changed the capacitors in the ECU?
http://www.clublexus.com/forums/ls-1st-and-2nd-gen-1990-2000/656360-all-my-crazy-lexus-issues-solved-ecu-leaking-capacitor.html