That's a little difficult to answer without knowing what kind of vehicle.
You will need to remove the throttle body and replace the throttle body gasket. The throttle body gasket can be purchased at most auto-parts stores.
The throttle body base gasket would be located between the throttle body and the intake manifold.
Between the throttle body and the intake manifold.
Check the throttle body over carefully to find the leak. If a gasket is leaking then a new gasket set will stop the leak. If the body has a crack then you will need to replace the throttle body.
I am not sure about the throttle body gasket. I know the flow tube should be replaced. Your problem may be that the flow tube is plugged up with carbon, which is very common with the acura egr system. More then likely there is a reason for the throttle body gasket to be replaced. there could be a link between a vacuum leak and the egr system at the throttle body.
You can adjust the idle from the throttle body. Replacing the throttle body might have accidentally change the idle speed. The idle speed adjustment screw can be turned either way to raise or lower the idle.
Disconnect the negative cable from the battery, Remove air filter housing, Relieve fuel pressure, wrap a shop rag around fuel line fitting before you loosen it, Disconnect vacuum lines, electrical plugs, throttle cable and fuel lines from throttle body, Remove bolts holding the throttle body to the intake manifold, Remove throttle body, Remove all of the old throttle body gasket material from both surfaces, Reverse procedure to install.
You may have a vacuum leak, check the gasket under the throttle body, spray some carb cleaner around the base of the throttle body while the engine is running. If there is a leak you will hear a change in the engine rpms.
Disconnect negative cable from battery, relieve fuel pressure, disconnect throttle cable, disconnect fuel lines, disconnect any vacuum lines, disconnect electrical plugs, remove bolts holding throttle body, lift off throttle body, remove damaged gasket, clean area, replace in reverse order.
Could be a vacuum leak. Check the throttle body base gasket.
It's under the throttle body. To get to it, you'll need to remove the throttle body and flip it upside down. The IAC valve is mounted by two screws to the throttle body, and it has a gasket that you will need to replace if you remove the IAC valve, so make sure you have a new gasket on hand if you intend to take off the IAC valve.
you need to buy the intake gasket throttle body gasket remove bolts from the intake both front rear and four bolts at the throttle body side remove the intake dont try to take out bolts to the plentum hex key bolts then remove the coils then the spark plugs all with the engine cold