Forgot to mention, that while you have it out, get a strong flashlight and put a ratchet on the crank. Then turn the crank by hand and inspect the impulse sending wheel for damage as it turns by shining the light into the hole in the block. A damaged impulse wheel will send the same code as a faulty CKP sensor. I checked the resistance on three different CKPs and got three different numbers; for that reason I do not feel that measuring ohms for these is a suitable indicator of their operability.
Also, it's A LOT easier to plug and unplug the pigtail with the sensor unmounted. I wouldn't even bother trying to (un)plug it while it's in there.
Get the area clean before removal. I took electrical contact cleaner and a detail attachment for a shopvac (basically a 3/8" hose) and got it spotless first. CAUTION: NEVER VACUUM FLAMMABLE LIQUIDS. FIRE AND/OR EXPLOSION WILL OCCUR. I made sure my contact cleaner was non-flammable before prepping the area.
You can test a CKP sensor by observing the voltage fluctuation that occurs when the motor cranks. However, for my car at least, the only way I could have done that and still kept the rest of the ecu wiring harness plugged in would've been to remove those specific pins from the connectors.
If I were to flowchart this in the interest of, say, an algorithm, these would be my steps and the order in which I would undertake them:
1. Remove and visually inspect CKP. Check for cracks and any marks indicating the impulse wheel may have made contact.
2. Turn the crank by hand and inspect the impulse wheel. There is a small smooth spot with no teeth, that is normal. Look for roughness that would indicate cracking and fracturing.
3. With the CKP unplugged, now check for continuity between the harness-side connector and the wire-loom connector to the ECU.
If your impulse wheel is okay and you have good continuity (no breaks) in the wires to the ECU, then it's probably your CKP.