Once the 4 Torx screws have been removed, the direct ignition system
can be gently lifted up exposing the spark plugs below. NGK
spark plugs, http://www.ngksparkplugs.com
can be used. The
correct spark plug and recommended gap can be obtained from
the NGK web site. Be sure to set the gap as specified.
Changing
sparkplugs on the Saab 900SE is about as easy as it gets, as long
as you have a standard 5/8 inch spark plug socket and a 6 inch
extension for your rachet. Remember NOT to overtighten
the
new spark plugs. They should be moderately tight.