2004 Ram 1500 4.7L, Went into limp mpde all of a sudden and then went to 1st gear and will not shift. Put my computer on the truck and got all kind of electrical codes. Replaced line pressure sensor. Got to thinking, with all the electrical codes there must be a common source. I took the IPM out and took it apart. A bunch of dead bugs and a huge moth carcass under the circuit board. Could this cause things to be shorting out? I dont want to reinstall the IPM if I need a new one. Circuit board looke fine just dusty, I did clean it.

 

I recommend you re-install the module and do some basic checks and maintenance.
All kinds of electrical codes could definitely be a computer, and could also be a more basic electrical problem. I've seen several people replace computers only to find the problem was a ground or some other electrical component.
I would check the grounds, battery, and alternator. Some good videos for this.
What were the electrical codes are you getting? Are you able to smoothly shift through the gears at a stop with the brake on?