Why does monitor says reduced engine speed then engine loses power on 2003 Chevrolet Silverado 2500 HD

This happens often. I pull over cut engine off for few minutes then restart some times it does it again. Put it on computer nothing shows up. changed gauges and other things and still doing it. it has 154,000 miles and receives regular maintenance. Help

seek diag from a good repair shop
1 more answer
Check your air filter if its dirty it will restrict the air flow and cause your motor to cut down so not to over heat