Q: How to clean the air intake system..

If the intake system (throttle body and intake manifold) are that clogged up, the safest route may be to remove them completely for a thorough cleaning. Cleaning it while still attached to the engine creates the risk of even the smallest bits of carbon falling into the combustion chambers. While they may just burn away harmlessly, they can also cause some damage. It’s not worth the risk. Plus, taking the time to remove the intake will make it easier and less time consuming to completely clean the intake manifold. The time spent to remove the intake system will be saved in cleaning time. Make sure you replace the intake gasket, and any other gaskets and seals associated with removal as to not wind up with vacuum leaks after reinstalled.