buick regal

Hello, Please help to identify the sensor in the center of photo? Car Regal LS 1997 V6 3800 series 2. Its on the passenger side at the very top of the engine, on opposite side of engine from MAF sensor. Thank you!

Long story short....I know where an above-mentioned car is sitting in a most unsuspecting garage. I got about a 5 second glimpse of it but with an inch of dust on it, it was hard to tell. Supposedly it has been parked there since being bought but that is just hearsay. But I do know that the guy...