Knock Sensor And Throttle Position Sensor

[lexlslove]

I recently had my check engine light come on my 1993 ls400. I noticed however that as I drive and accelerate the check engine light goes away. I then read the codes and saw the codes for the throttle position sensor and No. 2 knock sensor. Looking at lexls, I believe that I can do the TPS by myself but I have no idea where the No. 2 knock sensor is. A few months back, while changing out a bad starter, with the help of a mechanic friend, I changed a knock sensor out.

So can anyone tell me where to find the NO. 2 knock sensor?

Is the TPS and Knock related in a way that could cause one to "set off" the other?

[1990LS400]

See attached diagram -- both knock sensors are highlighted.

[lexlslove]

See attached diagram -- both knock sensors are highlighted.

Thanks i'm sure this will be extremely helpful.