RPM surges at idle, in gear & out of gear, and noticeable surges prior to gear changes. My dash lost power briefly (4 times - it was like I flipped a switch and the whole dash went dead)but came back on within 30 - 60 seconds, and the truck has shut off twice (with no trouble re-starting).
Batteries were replaced 6 months ago with addition of 4" intake and exhaust. Hypertech HyperPAC installed. Used Stage 1 (Stage 1= +37HP +64TQ).
Everything ran fine till about a month ago.
Fault codes on Hyperpac:
PO404: exhaust gas recirculator control circuit
PO405: exhaust gas recirculator sensor "A" circuit low

Have just cleared all codes, and will take for a test drive (to see if any codes re-appear).