YOU DON'T , REPLACE IT ... IMEAN THERE ARE TIMES THAT PEOPLE SAY CLEAN IT, BUT THATS A COMMON MISTAKE, YOU WOULD HAVE TO REPLACE IT.
i need to know where the speed sensor is in my mercury mystique so i can replace it.
replace it
replace the fuel pump, located in gas tank.
take it to authorized transmissions
by going to a body shop
Mercury Mystique with V6 engine has two oxygen sensors. First one located between radiator and engine, second - behind the engine, near the coil pack (below). It's not very difficult to replace them.
get a mechanic to do it...seriously... its not worth the aggravation...
98' headlights look better
Replacing ERG Valves in a 1998 Mercury Mystique is fairly hard because it requires great precision to avoid blocking the EGR passage.
http://www.installdr.com/InstallDocs/FLM/Contour.html
Duck tape should do the trick
Righty tighty, lefty loosey.