1995 ES300 Techstream unsupported?
 

I've had a problem with PO500 and PO720 and am starting to suspect the ECU... I've replace the "Vehicle Speed Sensor" (3-wire) but I don't see improvement... I'm using an Innova scanner, which works but takes time to link, and looking at the vehicle speed it jumps around from 0 mph to 7 mph to 100 mph... ... I tried using Techstream, it links (takes time) but I can't get any readings from it as it comes back saying "unsupported."

Don't know, but would not be surprised if it was not supported. 1994 ES300 was one of the first (if not first) vehicles to have OBD-II and as a result the system was in effect a beta version until 1996 when OBD-II became mandatory.