certainly worth a try with the O2 sensors. I know you can buy them cheaper on ebay. Otherwise you can buy them from places like Bursons, Autobarn, Supercheap, Motor Traders etc.

Ordered a new O2 sensor today from burson's for $50, will get it tomorrow It won't be going in for another couple of weeks due to the fact that I'm recovering from a knee reconstruction but as soon as it goes in i will let you guys know. Thanks for the help

another thing to try could maybe be checking for vacuum leaks... my el xr6 has done the same as yours for a while now but lately its getting a lot worse ever since ive noticed the intake manifold gasket appears to be leaking really badly. I'm assuming its had a small leak i havent really noticed for ages but now its worse. I've also heard of other people having problems with the same gasket on falcons. I havent gotten around to changing the gasket yet as i usually ride my motorbike but im hoping it will fix the problem as ive replaced a lot of things in the past trying to fix it.

Whats the TPS voltage at idle?
How much manifold vaccum at idle?
What fuel pressure at idle?
Does it happen when dead cold and hot? or just hot?
At operating temp what are the voltages from the coolent temp sensor?

Stop guessing and start a process of diagnosing the problem.