Knock Sensor Location

[zach1990]

ive got a 2000 gmc sierra z71 with the 4.8 liter (294) vortec. im going to replace my knocker sensors and ive read on all the different forums and in my chilton's manual that its located under the intake manifold yet both mechanics that installed my new tranny swear they saw it on the bottom passenger side of the engine where its located on older model chevys/gmcs. any input to this would be nice so i dont go sticking a sensor in the wrong place or waste time tearing apart an engine just to look stupid

[jerksville]

BOTH knock sensors are under the intake in the valley cover

 

Those "mechanics" arent very well educated in GM LS based engines then cuz thats were the knock sensors are on them

[zach1990]

BOTH knock sensors are under the intake in the valley cover

 

Those "mechanics" arent very well educated in GM LS based engines then cuz thats were the knock sensors are on them

 

thanks thats what i thought anyway ive been running it since 2009 with a trouble code for those sensors and im working on rebuilding that truck now that it has 280,000 miles on it so how important are those sensors. i read on one forum that they arent worth the trouble and then on another that replacing them will add major boost to performance and fuel economy so which one is it?