Hey guys!, so i am noticng lately when i am driving at various speeds and i let off the gas to coast for a bit that the engine seems to shudder a bit, i thought it might have been the tranny but the rpm's stay stable and the tranny does not change gears at all. would this be caused be an egr malfunction? does the idle air control valve open t all when you let off the gas to just coast, not stopped? I am at a loss here and dont want to pay the stealership to tell me something i know you guys can figure out, any help would be appreciated?

 

does it do it only when the engine is cold?