Chrysler 2008 Aspen - Manual (Page 395)

Spark Plugs
Spark plugs must fire properly to assure proper engine
performance and emission control. The plugs installed in
your vehicle should operate satisfactorily in normal
service for the mileage indicated in the Maintenance
Chart. New plugs should be installed at this mileage. The
entire set should be replaced if there is any malfunction
due to a faulty spark plug. For the proper type of spark
plug for your vehicle, refer to ”Spark Plugs” under
Fluids, Lubricants and Genuine Parts” in this section.
CAUTION!
When replacing plugs, do not overtighten. You could
damage them and cause them to leak.
Engine Air Cleaner Filter
Follow the Maintenance Schedule for recommended en-
gine air cleaner filter change intervals.
WARNING!
The air cleaner can provide a measure of protection
in the case of engine backfire. Do not remove the air
cleaner unless such removal is necessary for repair or
maintenance. Make sure that no one is near the
engine compartment before starting the vehicle with
the air cleaner removed. Failure to do so can result in
serious personal injury.
394 MAINTAINING YOUR VEHICLE