The 2004.5 – 2005 LLYs were replaced by the 2006 LLYs, which are entirely new engines. Aside from the programming, LBZ's... moreThe 2004.5 – 2005 LLYs were replaced by the 2006 LLYs, which are entirely new engines. Aside from the programming, LBZ's 2006 model includes nearly all of its upgrades.