if you're continuously having sensor codes coming up i would pay close attention to the wire harness and also check relays. The relays have been known to cause all sorts of issues that trigger codes that lead you down the wrong path in diagnosis. Also make sure your negative grounds are clean and tight (on the frame).

There are 2 relay boxes, one beside the fuse box and the other underneath the left step cover. I wouldn't rule out the fuse box either, i've seen the fuses work themselves out of their sockets from vibration causing issues as well. But to have sensors going bad on a single machine repeatedly is uncommon unless there is something else wrong you just havn't found yet.

Installing coil packs is not a no-brainer. It is way too easy to miss the plug and slide the boot alongside the insulator. At best, you have an intermittent cylinder; at worst, a fireworks show. In either event, the truck can throw an E27 or even an E43 code.

Learned the hard way:)

Yes we know when it is a coil pack, still just wondering if people are have trouble with these sensors. They are OEM

Are you positive it is the sensors and not the wiring? Those motors are notorious for the cam/crank wiring failing. might pull the harness apart and ohm it out to be sure.

Was trying to find out why we are going thru so many crank and cam sensors. We can repair the problem. just was curious if other people were going thru crank and cam sensors often.

A bad coil on a k21-k25 can cause a crankshaft sensor code. You can start the engine and disconnect 3 of the coils to determine which coil is bad. Then connect another coil and disconnect the one previously connected. Keep going till it has run on each cylinder by itself. These engines will run on 1 cylinder. The bad one will kill the motor when it tries to run it by itself.