After buying a 1994 ES 300 with 80,000 miles, about a month later the check engine light came on together with the "O/D Off" light flashing. Turns out there was some serious problems with the differential and torque converter. I had all these fixed, however after picking up the car the same lights have come on. The mechanic is baffled and keeps trying things to no avail. Has anybody had this happen to them? Any ideas as to how to cure this problem would be helpful. Thanks in advance.