My 2007 S with 57K has had the CEL come on multiple times in the last few months with the P2188 - Rich at Idle - code. They have replaced the valve cover due to a bad PVC, replaced a leaky hose (not sure which one), did the carbon cleaning, and replaced the fuel pump (probably not related to the P2188).

Most recently, they told me this was caused by sofware. Apparently I was multiple software versions behind.

Does this make sense to anyone? If the software was faulty, why didn't the CEL come on in the previous 7 years?

Thanks...