Had the same problem with my 96 es300. Bought the valve @ Carquest for $35. You have to remove the negative terminal from battery as you will be working around the passenger airbag. Disconnect the pass ABS through the glovebox then remove the glovebox, ECU, blower !Removed!'y, evap cover & then the coil will just slide out. Man it was filthy. 2 Screws hold the valve on. Make sure you get it in the right direction for flow. Took me a few hours with a service manual, but I've been in the commercial/industrial A/C industry since 1980, so it was no big deal to me. But I don't think it is a DIY project for the untrained. You also need to get vacuum pump and recovery equipment. I was able to borrow from a buddy. :D