A month ago I replaced the spark plugs. In doing this I had to disconnect several electrical connections (especially on the drivers side of the engine). I'm pretty certain I reconnected all of them, but I have my "check engine light" on and my "VSC" light on. The car runs perfectly and idles perfectly (better than before I changed out the plugs). I've tried to reset codes by disconnecting the negative battery terminal for a few minutes, but it did not turn off the lights. I've tried AutoZone/O'Reily's guys and their code readers, but they couldn't turn them off either. I know these codes are common after changing out these plugs....so how are people getting these turned off?? I really don't want to pay Toyota/Lexus $150 just to for them to use their high dollar scanner, when I'm sure there are no issues with the car. I keep checking and re-checking the connections and can't find any that I missed, but maybe that is the issue?!? I can'f find a diagram anywhere that lays out where all the sensors are to make sure I'm checking all the right spots. The times I had the codes read by AutoZone, etc....they come back "crankshaft position sensor". Where the hell is that located so that I can make sure it's been checked?? Anyone have some help or guidance for me on this?? Thanks !!

 

I changed the spark plugs myself and no codes at all, i did get a check engine and vsc lights codes at first but it was my fault, i disconnected a sensor and forgot to plug it back, in your case I'm pretty sure you left something disconnected. The cable I left disconnected by mistake was the following:
Knock sensor bank 1 i needed to disconnect it in order to take out the spark plug on the driver side

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But as soon as i replug it all codes disappeared

 

Crankshaft position sensor is part #11401G in this diagram:

 

You can buy the cable for $20 on ebay and run the same software Toyota runs to scan advanced engine codes and customize features.

See my demonstration video here: