The reason you're seeing the CEL come on as the engine warms up is because the ECU transitions to closed loop operation and starts using the O2 sensor. It sees an incorrect response from the sensor and gives you the light. If you want to check your ICV, pull it out and keep it plugged in on a running engine. The wheel inside should spin when the engine is running. It does sound like you have a massive vacuum leak somewhere based on your description. Check your oil dipstick too. It should seal in the tube and on my car it causes the idle to get shaky if pulled on a running engine...so it does have to hold back vacuum. Check the line going to the FPR. It runs under the intake and you won't see anything if its broken below the manifold. The PCV breather hose vacuum line connects around the same area below the intake manifold and can also be broken. I've replaced all of these lines on my engine and the old hoses felt like rock when I removed them. Old age isn't kind to rubber hoses. Inspect the connection to the brake booster too. That's a pretty big hose and could easily cause a huge vacuum leak if its cracked or broken. Those are just about all the vacuum connections that the M30 has. My money is on one of those hoses