Well my tach now stays right at 560 RPMs in drive and reverse, but when in Park or neutral it raises to 700. but when the car idles in park or neutral, from bone cold all the way to normal temperature, the idle surges. This is with the A/C off, because if i have a/c or defroster on the clutch makes a clacking noise every 5 secs, and the idle fluctuates 200rpms+. The idle surge in park/neutral is just enough to not show on the tach, but sitting outside the vehicle you can hear the idle surge up a little, back down a little, constantly. Could this be my IAC? I have dont the PI swap and tried both my stock IAC and the PI IAC by swapping throttle bodys, same problem. should i get a new IAC?