I have a 2007.5 Chevrolet 2500HD LTZ LMM. I am getting the above codes and the truck keeps saying reduced engine power. I have EFI Live, cold air intake and 5" exhaust. I have 5 tunes and they still seem to be working. I changed the fuel filter and cleaned the MAF with MAF cleaner. I have had the truck for about 4 weeks and everything was running fine till last Saturday. The guy that had the truck before me said that with EFI Live those codes should not come up. The codes are for Exhaust gas temp high, but those have been deleted with the 5" exhaust. I was wondering if anybody else has had this problem? I gonna give St. Joe Diesel a call tomorrow and see if they can help. I heard these guys are pretty good.
