Hard to start when cold and throwing P0115 code

Getting the code attached. I replaced the fuel pump and the truck now starts, idles, and runs great. The temp gauge is staying right in the middle.

My issue is that it is hard to start when cold, so I am assuming it's associated to the code. It needs a new air filter really bad so I am making a trip to the store tomorrow. Any ideas what could be causing the code? Egr was unplugged when I got the truck last week and I have tried resetting the codes and it comes back on within 3 seconds or so.

 

Maybe you're thermostat needs to be replaced.

 

Bad ecm or damaged harness especially if the code is triggered within 3 second.

 

Ok, I am hopefully taking it into a friend's shop tomorrow to check it out. If we can data log it we should be able to pinpoint it I would think

 

I would look at the Engine Coolant Temp sensor

That could cause the cold start problems

Not to be confused with the Gauge sending unit

 

So the truck is only hard to start in the morning. I ran a bunch of errands today after work, and the truck ran perfect, and started on the first try every time after I got it started the first time. I am kinda leaning towards the temp sensor. Anywhere else to look, still getting the code.

 

Anyone else see the issue-- stupid palm rats down here in Florida chewed thru one of the wires. I took the wiring harness out, fixed it and rewrapped with electrical tape and no check engine light and runs smoother.

Love an easy fix