Originally Posted by BoilerUpXFire

Based on my personal experience, and that of several others in this thread, I would try to just put some miles on it before messing with everything again, if you feel you installed it correctly. Several of us have simply needed to let time pass and the cars ECU to adjust to the new part. That is the only way I can explain it as I did every test in the book on mine, no vacuum leaks, no nothing and it was surging. I drove it a few hundred miles and have not had any trouble since.

Just a thought...