dude, I feel your pain on the knock sensor. You can ck the knock sensor by putting a ohm meter on it. I went ahead and replace the knock sensor which involve removing the intake manifold. Two days later the ck engine light came back on and found out the connection was dirty. All you need to do is clean the connection, place electric grease, and reset the ecu(or it will do it by itself). If u don't know where the connection is - it is about middle of radiator and zip tie to bottom of cross bar.

good luck.