What is wrong when I get both the check engine light and reduce power lights showing up on my dash?

Both lights come on and I lose power and slow down, petal is not responsive. Scanned for codes P2138, p0641, p2135, p0526 show up. Dealership thinks it's related to the 5V reference circuit. They check wire harnesses for visible damage and could not find any. They said they can't narrow it down and to bring it back in when it happens again. It happened again 2 weeks later. It was on a saturday so they could just scan it and see what codes it through off. It was the same as before. But seeing that they did not have the manpower to check into it that day I had to drive it around as is. Both of the above lights came on again at 5 different times.
After I bought it in September I went to an auto place and had a remote start put in. Could that have something to do with my issue?
I have also noticed that when I start my vehicle it races loud (roars)and then goes normal. And my fan seems to be louder or going faster than normal when I accelerate. These symptoms are new ever since my first check engine light came on.
I am at a loss for words. Any ideas?
Thanks