Stg2Suby
Active VIP Member
Neighbours 2015 GMC 1/2t with the 5.3 has developed a problem, engine vibrating at all RPM, almost like it dropped a cylinder. Very rough at idle. No codes thrown which is odd, no CEL or codes on the scanner. Went for a quick drive around the block and it really shudders. Any ideas, inherent issues etc? It did flash the CEL and the traction control lights on for a bit on the test drive but no stored codes.