Where is the throttle body located on a 1998 Expedition 4wd Mine keeps dying when you take your foot off of the gas?
The throttle body is where the air enters the intake manifold or plenum chamber. Follow your air cleaner tubing and at the end of this tubing where it actually goes into the engine is where the throttle body is. It will have a throttle plate (or butterfly valve) that opens and closes with the accelerator cable. This square unit is the throttle body. Before you get to this there will be a large sqaurish shaped sensor with connectors going to it. This will be the Mass Air Flow sensor. Dont confuse this for the throttle body. In order to get complete access to the throttle body you might have to remove some plastic pieces that cover all this up and supposidly make the engine look tidier. Make sure your air filter isn't just clogged up first. Hope this helps.