'03 tahoe with a 5.3 experiencing intermittent limp mode that generates a p1516. Wiring and connectors to throttle body look good, throttle plate is free. Any common concerns out there? Thanks!

From a write up I came across:

There is a yellow wire coming off the connector that breaks internally, pull on it from about 5" away from the connector to see if it feels spongy or if it pulls free.

There is a ground at the back of the passenger side head that becomes loose and needs to be tightened up.

Sometimes the actuator on the throttle body can bind up and cause this code.