Here is everything i did to my car and it's been working perfect for almost 2 months now.
First cleaned the ICV (Idle control valve).
Next tested the TPS (Throttle position sensor). tested with a multimeter and it was working fine. This video will help if u don't know how to test one.
Changed the fuel filter and dumped a couple fuel injector cleaners in.
I took out the ecu opened it up and noticed there were some brown spots on some of the little solder points, so i bought a fine point solder gun and touched all of them that were brown. I was told that over time those solder points can get a small crack in them and well, cause it not to run right.
I put a cold air intake on it, and that's about it.
It only started running properly after i re-soldered the ecu and put the cold air intake on it but i donno. Maybe it was just the injectors were still clogged with dirt and over time they got cleaned out. I only run supreme in it cuz that's what they call for.
Hope this helps you, i know i was getting pretty frustrated with it.
Also here is a sweet DIY site i go to a lot, maybe it will help you.