To replace crank sensor or not?...

Buddy of mine said he had the same '96 XJ 4.0 as me and suggested I should go ahead and pro-actively replace my crank sensor as his went bad. I've had mine 10 years now from 88,000 mi when I got her til 170,000 miles now.

Should I go ahead and replace the crank sensor? Seems like a fairly inexpensive piece and I'm guessing it won't have to be replaced again.

Couldn't hurt, especially if you feel it's an inexpensive part. When the cam or crank sensors go, they generally leave you on the side of the road with no spark, and the crank sensor seems to be the most common cause for no spark. I know one guy who had intermittent, heat-related poor driveability with a 4.0 in a Wrangler, turned out to be the crank sensor. If you do buy a new one, buy the best one you can. OEM Mopar sensors can be surprisingly affordable. Jussayin'...

Guys here will also tell you that they can reach the crank sensor from the underside of the Jeep with things like "every 3/8" extension I own" and "small children." They're full of hot air. In my experience, it was much easier to pull the air box and try to get to the crank sensor from underneath the intake manifold with a 3/8" ratchet, a short extension and a crow's foot.