Need help I'm getting a p040d and p2262 code
 

i have a 2011 ram 2500 it's been deleted straight exhaust and a torc tec programmer and I keep getting these two codes and the truck acts like the exhaust brake is randomly coming on when driving it has no throttle response when it dose it if you let off the gas everything goes back to normal it may do it once a day or it may do it 10 times it's never the same