Anyone know where and what this plug goes to on a 00 blazer? its on the pass side of engine bay towards firewall.

 

Looks like a Knock Sensor connector, (top rear of engine)
The knock sensor has a Dark blue wire, you didn't mention what the wire color is.

 

its not my blazer, buddy sent me the pics to post. ill go look on mine and see if i can find it.

 

Thats what it went to, thanks!

 

Yah! defintently the knock senser connecter,but that was not easy to get to with the feul lines right over the top of it. Or that could just be on mine. Was it getting bad feul mileage just corious what it would do to the vehile if not connected, or why someone would disconnect it at all? They are not very easy to get off. Does the truck have the original motor or you dont know? OR care!

 

Hes putting another motor in, guess the day everything got unplugged it was a free for all, hands everywhere...and he had no clue where anything went, and...that was last year...lol.