FORD 1998 F-150 - Manual (Page 191)

identifies engine displacement and
gives some tune up specifications.
Please consult your “Warranty
Guide” for complete emission
warranty information.
Readiness for
inspection/maintenance (I/M)
testing
In some localities, it may be a legal
requirement to pass an I/M test of
the on-board diagnostic (OBD-II)
system. If your “check
engine/service engine soon” light is
on, reference the applicable light
description in the Warning Lights
and Chimes section of your
owners guide. Your vehicle may
not pass the I/M test with the
“check engine/service engine soon”
light on.
If the vehicle’s powertrain system
or its battery has just been
serviced, the OBD-II system is
reset to a “not ready for I/M test”
condition. To ready the OBD-II
system for I/M testing, a minimum
of 30 minutes of city and highway
driving is necessary as described
below:
• First, at least 10 minutes of
driving on an expressway or
highway.
• Next, at least 20 minutes driving
in stop and go, city type traffic
with at least four idle periods.
Allow the vehicle to sit for at least
eight hours without starting the
engine. Then, start the engine and
Maintenance and care
191