The ability of the fuel system to control hydrocarbon emissions is dependent largely on a leak-free
system. Check for proper sealing of gasoline filler cap which contains "O"-ring type seals. Check all
evaporative hoses in vehicle for tightness. Check fuel lines under vehicle. Repair if necessary.
Air cleaner
Replace the air cleaner cartridge every 30,000 miles (48,000 km). The cartridge should be replaced more
often when driving under dirty and/ or dusty conditions.
The filter cannot be cleaned and should always be replaced with a new one.
Checking and adjusting idle speed
Your Volvo is equipped with an electronically controlled idle speed system that requires no period
checking or adjustment.
Lamda-sond (oxygen sensor) system
This is an emission control system designed to reduce emissions and improve fuel economy. An oxygen
sensor monitors the composition of the exhaust gases leaving the engine. The exhaust gas analysis is fed
into an electronic unit which continuously influences the amount of fuel injected. This adjusts the air-
fuel ratio to provide optimum conditions for combustion and efficient reduction of the three major
pollutants (hydrocarbons, carbon monoxide and nitrogen oxides) through a 3-way catalytic converter.
pg. 79 Servicing
Oxygen Sensor
