2016 Altima with a P0776 error code. It sporadically loses power when accelerating. The dealership claims the transmission needs to be replaced for $6k. I took it to a transmission shop because I've read about people having luck with a simple fluid change; however, the shop recommends not changing the CVT fluid because it has more detergents than any other fluid in the car. They said as my transmission is heating up the detergents are breaking down and this could create more problems. Thoughts or suggestions?