2002 sable engine hesitates at 35 mph

[prrk]

My vehicle started to hesitate at about 35 mph and when given gas it goes away. This happened over night. Looking under the hood I observed a small wire was eaten by an animal. This wire connects to a spark plug looking item in the very front of the engin and looks like it is near the exhause of manifold. It actually has 4 small wires that then connect to some plastic connector.. I originally thought this was a erg valve but discovered it was not. This can be found right behind the radiator. I have not been able to recconect the wires because they were chewed so close to the spark plug looking thing. I attempted to take itoff so I could work on connecting it but have had no luck yet.
2 questions....
1- what is this called an what is its purpose.
2- can I run the car without reconnecting it.

thanks pk