You've made a mistake by not creating a new thread and posting in one from 2009.
Its okay to reference old threads in your new one, but bringing it back from the dead is something we frown upon.
Moved your thread.
Despite you not appreciating Nixon's comment, insulting him isn't a great path to go down.
You're no longer in the right, but right there with Nixon.
As for your issues: Why would you sell a car in this manor? Thats pretty backwards.
You can't tune the code out because you can't touch your PCM.
You can get one from Will for a large cost, may or may not work. Depends on the make of the PCM.
Or get an 05 PCM, then your fuel gauge will read backwards.
