here is a little tip that I learned a few days ago. I have the SDA cams (not sure which ones) in my 98 sl2. I just put my manual computer back into the car and I have been getting a vacuum code. When you run a bigger cam in a car naturally it will require more air. A normal Sattys idle is at about 850 to 900ish RPM, mine with the cams was at about 735RPM How to adjust for that is by the idle screw found at the bottom of the throttle body. most of the time it has a little rubber condom thingy on it so that the idle adjustment cant be messed with from the factory.
How to adjust the idle is as follows:
turn on car and let it get to normal operating temp.
got to the throttle body and SLOWLY start turning the screw CLOCKWISE. You will get to a point were the cars idle will spike to about 2 grand. this is because the IAC valve is not adjusted. When this happens go into the car and shut it off with the high idle still going. wait a minute or two and then start it again. The idle of the car should be SLIGHTLY higher
go back to the idle screw and turn slightly more to the clockwise direction. If the idle spikes again just go into the car and shut it off and let it sit. By shutting the car off you are letting the IAC valve reset itself and adjust for normal idle.
keep on doing these procedures until the desired idle is reached. JUST REMEMBER TO TURN THE SCREW SLOOWWLY.
Once again if the idle spikes, which it will leave it be, and go and turn the car off. By doing these steps I have raised the idle in my car from 735RPM to About 850ish RPM. This will also get rid of that vacuum code that is associated with adding a bigger cam so you can pass inspection
I hope my mindless rambling was helpful