The SES light came on yesterday. Advanced Auto read the codes and the following came up. PO734 -Gear 4 Ratio Incorrect an PO174 System Too Lean Bank 2 and PO171 System Too Lean Bank 1. In searching the forum it seems I should check the gas cap and the MAF sensor. Any other ideas? I need help in locating the MAF. I would also like the steps in cleaning it. New to LR ownership and will be ordering a service CD as it seems it will be necessary and helpful. Does anyone have a good source for the CD manual? Thanks for your replies.