Please help with check engine light...

[guitar3228]

ok 1996 240sx SE

symptoms: engine idles low when warm and especially when in reverse, and this things running rich and guzzling gas....

the check engine light is on and the computer is throwing 3 codes the first code says IAT (intake air Temp) sensor malfunctionthe second one says O2 Sensor (doesn't say which one) malfunctionand the last code says something like emissions problem

im not about to buy any sensors until i know the real problem, but has anyone had this problem before, or have any idea what might cause these three codes to pop up????
Modified by guitar3228 at 8:49 PM 7/28/2008