Chris, You will reach only a small part of the air intake system by spraying in the air flow meter. Naturally the best way is to remove the W or horn pipe on front and clean it inside and clean the throttle body butterflies so they will seat properly, But the best way is to take it apart by sections and clean it. No harm will come by using the spray's for that purpose but you would need to relubricate several parts in the system because the spray will take away the oil that is there. When you push down in the air intake plate there are three pivot points that will loose the oil or lubricate that is in there now. That would be the main problem I would see. John Hervey specialTauto.com << Are there any consequenses of spraying carb cleaner inside the top of the fuel injection system (without air cleaner)with the engine running? I noticed for the first time today I have black build-up (which has only recently started) inside the intake and on the diaphragm entering the system. I warmed the engine and sprayed a spray-style carb cleaner into the top while running the engine around 2000 RPM. It belches a horribly poisonous smelling cloud when you do this. Will this spray-style carb cleaner harm the engine, exhaust, catalytic converter, or especially the O2 sensor? I just had a new O2 sensor installed and I don't want to ruin it. Anyone? Is there a different recommendation? Or can I do this safely? Chris #3876 >>