When I am going down road my truck will miss, when the check engine light comes on and the tach dies. As soon as I turn truck off to read codes the check engine light goes out and no codes will show up. I have been told this is the crank sensor, I would like moe opinions before I start replacing things.

 

thats what it sounds like to me.

 

also could be your throttle position sensor...does it do that if the cruise is on? if it doesn't with the cruise on that might be it. if the TPS is out it will cut back to an idle when ur accelerating and u pump the pedal it lights back up or it will just dead pedal on ya. also after it does it 3 times before your truck is started and shut off three times your truck saves it to the archives and you will be able to read it with the scan tool. the part were you cant read it with a scan tool is kinda wierd....hope its helpfull for ya! goodluck

 

That was it!!!!!!!!!!!!!!!!