Cool Z

I have an 02 LS6 cam in my M6 2002 SS. The only other mods are a lid and cat-back with LS1 edit. Anyways, since the install of the cam, my car no longer goes into de-accel fuel cut off. It will if I use rediculous down-shift practices (ie:70mph shift down to 2nd and let off the clutch). I noticed the thresh-hold is around 15kpa (MAP sensor value) and I know the enble speed is 1900 RPM's and dis-able is 1200 RPM's but how do I go about to change the KPa threshold. When I would like the DFCO to engage is at around 20 KPa with A/C off and 22 KPa with the A/C on stock is like 15KPa A/C off and 17 KPa A/C on. I do not fully understand how to change the values.

The next part is the throttle follower. Before the cam when rolling 60MPH and holding the clutch in, the engine would idle at 1600 RPM's and then as I slowed to 40 MPH it would drop to 1400 RPM's and them at 20 MPH it would drop further to 1000 RPM's untill I came to a stop and then after about 2 seconds at 0 MPH it would drop to idle. With the cam, as soon as I hit the clutch and remove my foot from the throttle, it goes straight to idle. I know some like it this way, but I don't. I makes the car harder to drive smoothly. I know there is Park/Neutral decay but I need some guidance as to how to make these fine adjustments.
Any help is greatly appreciated as always