Replaced commputer' code scanners reads egr valve. ' that. Part has been replaced' a couple of years ago' I took the truck to have ac work done on it. The day I took it over to the shop it wouldn't start I replaced the coil an it ran just fine when I took it over there' now when its started runs fin for a couple of min then starts missing an when u put it gear it wont hardly pull likes its in od