catalytic converter JEEP WRANGLER JK 2018 Owners Manual

— Engine Check/Malfunction Indicator Warning
Light (MIL)
The Engine Check/Malfunction Indicator Light (MIL) is a
part of an Onboard Diagnostic System called OBD II that
monitors engine and automatic transmission control sys-
tems. The light will illuminate when the ignition is in the
ON/RUN position before engine start. If the bulb does not
come on when turning the ignition switch from OFF to
ON/RUN, have the condition checked promptly.
Certain conditions, such as a loose or missing gas cap, poor
quality fuel, etc., may illuminate the light after engine start.
The vehicle should be serviced if the light stays on through
several typical driving styles. In most situations, the ve-
hicle will drive normally and will not require towing.
When the engine is running, the MIL may flash to alert
serious conditions that could lead to immediate loss of
power or severe catalytic converter damage. The vehicle
should be serviced as soon as possible if this occurs.

CAUTION!(Continued)
•If the MIL is flashing while the vehicle is running,
severe catalytic converter damage and power loss
will soon occur. Immediate service is required.
Onboard Diagnostic System (OBD II) Cybersecurity
Your vehicle is required to have an Onboard Diagnostic
system (OBD II) and a connection port to allow access to
information related to the performance of your emissions
controls. Authorized service technicians may need to ac-
cess this information to assist with the diagnosis and
service of your vehicle and emissions system.

CAUTION!(Continued)
the event of engine malfunction, particularly involv-
ing engine misfire or other apparent loss of perfor-
mance, have your vehicle serviced promptly. Contin-
ued operation of your vehicle with a severe
malfunction could cause the converter to overheat,
resulting in possible damage to the converter and
vehicle.
Under normal operating conditions, the catalytic converter
will not require maintenance. However, it is important to
keep the engine properly tuned to assure proper catalyst
operation and prevent possible catalyst damage.
NOTE: Intentional tampering with emissions control sys-
tems can result in civil penalties being assessed against
you.
In unusual situations involving grossly malfunctioning
engine operation, a scorching odor may suggest severe and
abnormal catalyst overheating. If this occurs, stop the
vehicle, turn off the engine and allow it to cool. Service,
including a tune-up to manufacturer’s specifications,
should be obtained immediately. To minimize the possibility of catalytic converter damage:
•
Do not interrupt the ignition when the transmission is in
gear and the vehicle is in motion.
• Do not try to start the vehicle by pushing or towing the
vehicle.
• Do not idle the engine with any ignition components
disconnected or removed, such as when diagnostic
testing, or for prolonged periods during very rough idle
or malfunctioning operating conditions.
Cooling System