Last night my 4.3 and trans started acting up. It felt sluggish when taking off from 0 and also wont go more then 3k rpm and the rpms moves up and down while keeping the gas pedal in one spot untill you push it more. The transmission wont shift unless you let off the gas.

I hooked up a scanner and got P0404 for the EGR being stuck open. I checked the TPS it is still good and also the trans shift in every gear only when you let off the gas. While i was driving home from work it had no power when driving up a hill.

Will the EGR be causing my engine and trans to act that way or could it be a clogged cat?