If you have a 1992-1996 Ford Crown Victoria, Mercury Grand Marquis, Lincoln Town Car, or possibly others with a Ford 4.6L engine, these instructions are valid.
These cars have an EGR passage along the back of the throttle body that is know to frequently fill up with carbon deposits. Usually the only symptom of this is a huge decrease in fuel economy, though it’s possible for this to cause a lack of power and/or check engine light.
It’s easy to clean, but in a tight area. Here are some pictures showing where this passage is and what it looks like:
The only good way I know of the clean this passage is with a screwdriver and a shop vac. Scrape the carbon out while the shop vac is running down there to keep it from falling down into the intake. After the big pieces are removed, you can clean it with a small brush and either throttle body cleaner or carb cleaner. There is also a tube that runs from the left side of this passage into the EGR valve – it’s not a bad idea to clean that out as best you can while it’s accessible. A stiff wire can be run through that tube to knock as much as is possible loose, again using the shop vac.
These gaskets can generally be reused, but if for some reason they don’t seal new gaskets can be purchased for under $1 through the internet. I keep several on hand and just replace them anytime I have it apart.