Hey guys, I have an 05 LLY. I started having issues with the engine kind of jumping like a misfire at around 45 to 50 mph at 2000rpm, I took it to the dealer where they changed the fuel filter and put injector cleaner thru. didn't help, so the tested the injectors all read fine, so they did a cylinder test. #7 came up low but low enough to be a bad seal or cracked piston head, also they said it wasn't a head gasket. it hasn't thrown any codes. Im lost here now, I have a egr blocking plate and finger stick in and straight piped. Im pretty sure the dealership is gonna really screw me over on my warrenty as well because of that. They said because I got rid of my cat it might have bent an intake valve, any help or ideas would be great.