Tried these mods?
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7978130373&category=33597

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7978962219&category=38634&sspagename=WDVW

save your money.. the first one is just a 50 cent resistor you can get at Radio Shack that makes the computer think it's colder out than it is, thus causing it to stay in "closed loop" mode (like a carb car with the choke on all the time) and use more gas, and the second one is just a total waste of money that only increases performance by making your wallet a little bit lighter and thus causing the engine to have to move less mass around- unless you count the weight of the thing, of course.
the first one defeats the emmissions control and fuel economy features on the car (a federal offense- so not 100% legal as stated), and the second one is something that if it worked half as good as they claimed, the factory would have installed it themselves to gain a little bit of fuel economy.