Volvo 700 » Pre-Heat Hose

This aluminum flex hose often gets torn and ends up hanging from the left side of the engine compartment. The purpose of this hose, when hooked to the heat riser pipe on the exhaust, is to route warm air to the air filter box. This is especially useful in colder climates because it helps speed the warm up of the engine. This reduces the emissions and helps the car run as designed. Also, a car may fail emissions testing if the pre heat hose is missing or torn.