Sheared off knock sensor

so I am replacing the head gasket on my 95 3.4l.
While I have my engine this torn down - I am replacing the knock sensors and wiring harness. When tightening the new one to 29 ft lbs it sheared off. Can any one tell me
A: does this happen often?
B: how do I get it out?
C: a quality replacement that won't cost me 500$

Please note I am a very mechanically inclined female who is brave- but still sensitive. Please be nice.

 

if theres no center hole, make one with a drill bit...
Then use an extractor.....

If you didnt send the head out to the machine shop, just have them do it for you....
Dont put that head back on without machine work...

 

Was that the correct location for the sensor?
The left side hole next to the missing cam cap?
I dont know, but looks like an odd location.
I can see what looks like a broken off threads in that hole..

 

Don’t the knock sensors go in the valley on the top of the block?

 

Knock sensors go in the valley between the heads usually

 

Ya on the top of the actual “engine block” @b_r_o

 

Yes. They go on the block... (sorry for the confusing picture- I am proud of how pretty it looks)

The threads are sheared off in the correct spot. I was able to back it out with ez-out. But can anyone speak to knock sensor replacements? Store/brand? They are $187.83 EACH from local toyota parts dept.
I purchased the sensors I sheared from Amazon.
I need advice because once I get this engine back together..I don't want to take it apart.

Thanks

 

Oem knock sensors. You'd be super irritated if you had to take it all back apart. And get a harness too, they get crispy and brittle

 

My harness crumbled upon removal. Thanks . I will be frugal on the starter or whatever part I can swap out easy.

 

Holy cow! I see two from Ourisman, $161 and $143.