Last Wednesday after returning from a trip my Xfire didn't want to start after not having run for 14 days. It ultimately did and I drove over to the post office. Then, in the post office parking lot, it would not start. Long story short: called nearby shop, called AAA and got frustrated while wading through their call tree, hung up, used code reader to get P0335, tired starting it again and it did. Took car home, ordered Bosch part, and installed it.

Here's are few additions to onehundred80's excellent "Replacing the Crankshaft Position Sensor- Rev.4":

1. I didn't need a flexible extension. I used a combination of short, but not too short, extensions. A "wobble" extension of appropriate length will work as shown.
2. Have a magnetic pickup nearby to assist in retrieving the bolt when it falls after removal.
3. A standard size needle nose pliers (pictured) works well when you need to rotate the new sensor so that the bolt holes line up.
4. That E8 bolt head is a nuisance! I couldn't get my fingers into the narrow channel. The bolt head won't stay in the socket for insertion. Screw starters didn't work. Couldn't find any of that gummy adhesive that attaches things in paper mail. Aha, the solution--a piece of paper towel! Place it over the socket's mouth and push in the bolt head. It worked. (see photo)