Welcome to the site. The 2003s are covered by a 7yr/200,000 mile warranty for the injectors only for high return rates and fuel in oil. Injectors will cost about $350-400 a piece and a whole lot of your time. (you have to pull the valve covers) I believe if the dealer does it and has to change them you are looking at $4-5000. I would have the dealership check the balance rates on the injectors and give you a print-out. In park they should be +/- 3 and in drive they should be +/- 6. (from 0) It does sound like a good deal, but I would be leary of this one unless it has full documentation of all maintenance.