So it's a 2000 S4 in pretty good shape, like 120k on the odo, but i had a pre purchase inspection done (at a cut-rate shop due to sellar not having enough time, I don't think I can get it to Audi before buying)but it's throwing codes P1606 (Mfr Ctrlled computer output ckt) and P1296(Mfr Ctrlled fuel and air metering).He said the 02 sensors might be going or they might just have sent out a code after being disconnected. Also the abs module is not connected but he has it. Could either of these be the cause of the error codes??? How much for a new O2 sensor if needed? It also needs valve gaskets, both sides, quoated at $350 P+L(fair price?) but I think I can get that off the purchase price. I'll have to pay for a couple tires, tail light and all 4 new rotors though. Also appears to have original timing belt and turbos. So timing belt asap and ko4s when the stockers go.(would I save a considerable amount of labor hours by have the tbelt and turbos done at once?) Anybody with any insight into this situation would be a life saver! Let m know if you feel this could be a reliable car or what migh be causeing my codes or just anything you wanna talk about B5 realated lol. He owns a few b5s and this one is in great shape plus it has all the options I want. Also this will be the third one I have owned so I'm not a total newb, but far from experienced lol[/QUOTE]