most likely is leak on the blanking plate.
also possible got vac tube mixed up and its holding egr butterfly on all the time.
there has been a couple over the years that lost performance or fuel economy, tho never found what the cause was.
also possible got vac tube mixed up and its holding egr butterfly on all the time.
there has been a couple over the years that lost performance or fuel economy, tho never found what the cause was.