So I have been having some problems where my 04 5.9L with 240k stalls out on me while driving. After trying just about everything under the sun, I noticed it will only happen if my key is in the ignition. If I start the truck, take it out while running, and drive off I’m fine. If I leave it in, I’ll die a mile down the road. Any ideas where I should start in terms of resolving this?

 

It sounds like your ignition switch is worn out. It is fairly easy to change out and you should be able to keep your original keys. On a side note, if you have a lot of keys on your key ring, it will put extra stress on the assembly.
Back to morning brew . . .

 

Did you ever figure it out, it could be the oil pressure sensor, I believe that the oil pressure sensor is run through the E C M it senses low pressure it cuts the fuel back so you don’t burn the engine up I believe in your earlier post you mentioned the oil pressure would fluctuate, the sensor is behind the fuel filter housing , do a google search 👍