The South African retired in 2006, having designed all of Michael Schumacher's winning cars, both at Ferrari and previous team Bennetton.
A Ferrari spokesman said that Byrne was working on a new Enzo road car project and will also provide "operational support" on the 2014 project.
German magazine Auto, Motor und Sport quotes Byrne himself as saying that he was "working full steam" on next year's car and said that 2013 car is looking like "child's play" in comparison.
The 69-year-old moved to Ferrari in 1997 to create a 'dream team' alongside Michael Schumacher and Ross Brawn.
Byrne had been involved as a consultant for Ferrari since his retirement in 2006.