So I only have one valet key to my 1998 LX 470. I've done my homework and it looks like Mauser is the resident expert. He has offered to send my a "virginized" EÇU to swap with my existing one so I can add a couple of master keys. I found the ECU with no problem (and discovered I need to change my cabin air filters lol). Is there anything I need to know? Can swapping ECU's cause an issue? I obviously trust Mauser (because you guys trust him and who else does this stuff just for donations to a food bank?) Just curious if anyone has gone this route? Seems strait forward 1) Disconnect the battery 2) remove old ECU 3) install new ECU 4) hook up the battery and the ECU is then in program mode allowing new keys to be added. Am I missing anything? Again Mauser seems to be a very honest stand up guy and I have no doubt he knows what he's doing... just looking for gotchas.