I have a 2012 Chrysler 200 with the 2.4.

I removed the 10 mm bolt from the old sensor.
while re installing the bolt with the new sensor it fell and got lost in another dimension. I have looked every where.
Does anyone know the size of the bolt so I could get a replacement?

 

Talk to the guy at the parts counter at your nearest Chrysler dealership. He will be able to pull up a parts drawing for you to look at so you can identify the correct bolt. Hardware store bolts may be the correct size but may not be the correct grade (strength). You might get lucky and save 59¢ by buying it from the hardware store instead of the dealership, but for that kind of money, you might as well get the right part. Let's hope the old bolt doesn't work it's way into some place where it can cause trouble.