Exhaust Emission Control System, Petrol: Other Saab 9-3 I

Lubricant

LUBRICANT SPECIFICATIONS

Crankcase ventilation

1. The exhaust gases passing the pistons and piston rings must be allowed to exit the engine. If the crankcase gases are not evacuated, the pressure in the crankcase will continue to increase until something gives. The crankcase gases must not pass into the engine bay, as they contain large amounts of unburnt hydrocarbons. To evacuate the gases, there is a system that recycles the hydrocarbons and lessens the pressure in the crankcase. See «Crankcase ventilation (B235R, B205L/R)»(ref-206763-S07133378582005112600000) .

Three way catalytic converter

1. To reduce the amount of harmful exhaust gases, the car is equipped with a three-way catalytic converter. The engine's exhaust gases pass through the catalytic converter where the catalytic material starts a chemical process. Provided that the closed loop fuel injection system maintains the fuel-air mixture at an optimum level, the catalytic converter reduces nitrous oxides (NOx) and oxidizes carbon monoxide (CO) and hydrocarbons (HC). The end products are carbon dioxide (CO2), water (H2O) and nitrogen (N2). The catalytic converter can reduce emissions provided the fuel is unleaded, since lead destroys the active components in the catalytic converter. In order to attain complete exhaust emission control in the shortest possible time in accordance with demands for LEV cars (Low Emission Vehicle), there are two catalytic converters fitted in series on these cars. The temperature of the catalytic converter must be kept high and by fitting it so close to the turbocharger outlet as possible, it will heat up faster and start to work earlier in the process. The capacity of the front catalytic converter is not sufficient for the complete emission control process, so a second catalytic converter has also been fitted. Diagnosis is performed by 2 oxygen sensors located after the first catalytic converter. The dual catalytic converter system has been introduced for reasons of space. To heat up the catalytic converters as fast as possible with the exhaust gases, T7 will increase idling speed and retard the ignition for a period after starting. This increases engine temperature. Both are three-way catalytic converter, i.e. they control emissions of CO, HC and NOx. See «CLOSED LOOP FUEL INJECTION SYSTEM»(ref-206763-S27033129352005112600000) .

Closed-loop fuel injection system

1. The catalytic converter has a high conversion ratio within a very narrow range. If the fuel-air mixture is not kept within this range, one or more gases will exceed permitted limits. A closed loop fuel injection system guarantees a correct fuel-air mixture. The level of oxygen is measured by an oxygen sensor that informs the Trionic or Motronic engine control module. The control module governs the fuel injection pulses so ensure the correct fuel-air mixture. See «CLOSED LOOP FUEL INJECTION SYSTEM»(ref-206763-S27033129352005112600000) .

Evaporative emission system

1. Hydrocarbons that vaporize in the fuel tank are passed through a pipe to a container filled with active carbon (EVAP canister) and are stored in the active carbon while the engine is stationary. The fuel vapour is then drawn into the engine and burnt together with the ordinary fuel mixture when the car is driven. All LEV cars are fitted with ORVR. See «EVAPORATIVE EMISSION SYSTEM»(ref-206763-S35421296782005112600000) .

Deceleration device

1. The deceleration device (not B235R) prevents emissions of unburnt hydrocarbons during engine braking and is integrated in the IAC valve. See «DECELERATION DEVICE»(ref-206763-S33414760922005112600000) .

The combustion gases flowing past the pistons and piston rings must be allowed to pass out of the engine. If the gases in the crankcase are not evacuated, the pressure in the crankcase will continue to rise until something breaks. The crankcase gases must not be allowed to pass out into the engine bay as they contain a large proportion of unburnt hydrocarbons. A system which recovers the hydrocarbons and prevents the pressure in the crankcase from rising excessively is used to evacuate the gases.

Identifying Crankcase Ventilation (B204i - 1 Of 2). Scheme 34

The crankcase ventilation system is completely closed. It consists of a nipple on the camshaft cover from which two hoses run to the throttle body.

The hoses and their connections are sized to provide satisfactory evacuation of the crankcase gases under all operating conditions.

The gases in the crankcase pass from the nipple in the camshaft cover to the throttle body through a thin hose and a thick hose. In the throttle body the gases are mixed with the intake air and burned in the engine.

When the engine is run at low and medium throttle, the crankcase gases are passed to the throttle body through the thin hose connected after the throttle. At full load, the gases are passed through the thick hose connected before the throttle.

On the turbo engine the thin hose connected after the throttle is fitted with a check valve which prevents the buildup of overpressure in the crankcase.

Identifying Crankcase Ventilation (B204i - 2 Of 2). Scheme 35

On the turbo engine a pipe replaces the thick hose connected before the throttle valve on the normally aspirated engine. This pipe carries the crankcase gases to the turbocharger's intake pipe.

Identifying Crankcase Ventilation (B235R, B205L/R). Scheme 36

The combustion gases flowing past the pistons and piston rings must be allowed to pass out of the engine. If the gases in the crankcase are not evacuated, the pressure in the crankcase will continue to rise until something breaks. The crankcase gases must not be allowed to pass out into the engine bay as they contain a large proportion of unburnt hydrocarbons. A system which recovers the hydrocarbons and prevents the pressure in the crankcase from rising excessively is used to evacuate the gases.

The crankcase gases are carried to the external oil trap via a nipple on the camshaft cover.

The gases are then evacuated to the turbo inlet pipe where they are mixed with the intake air and burned in the engine.

A drainage hose runs from the oil trap down below the oil level in the sump

The system is water-heated to prevent it from icing up.

Identifying Closed Loop Fuel Injection System (General). Scheme 37

General

The system is controlled electronically by means of an oxygen sensor located in the exhaust pipe ahead of a catalytic converter. The catalytic converter contains a ceramic or metal insert, the walls of which are coated with the catalytic materials platinum and rhodium. The catalytic converter is highly efficient within extremely narrow limits. If the fuel-air mixture is not maintained within these limits, one or more gases will unfailingly exceed permissible values. A closed loop fuel injection system ensures that the fuel-air mixture will be correct at all times.

Provided that the closed-loop fuel injection system maintains the fuel-air mixture at an optimum level, at which carbon monoxide (CO) and hydrocarbons (HC) are oxidized, the three-way catalytic converter can also reduce the amount of nitrous oxides (NOx). The end products will then be carbon dioxide (CO 2 ), water (H 2 O) and nitrogen (N 2 ). The ability of the catalytic converter to reduce emissions is conditional on the car being run on unleaded petrol.

This is because lead destroys the active components in the catalytic converter.

Identifying Closed Loop Fuel Injection System (Oxygen Sensor). Scheme 38

The oxygen sensor consists of a primary cell with solid electrolyte. The electrolyte consists of ceramic zirconium oxide and is temperature-stabilized through the addition of a minor quantity of yttrium oxide. The electrolyte is tubular and hollowed out at one end. The casing is coated with titanium and therefore electrically conductive.

When the motor runs on a lean mixture the oxygen content of the exhaust gases increases. The oxygen sensor voltage then drops and the engine control module reacts by extending the injection time. At a closed-loop value of 1.0 the voltage is about 0.45 V.

Since the oxygen sensor does not become effective until its operating temperature exceeds 600°C (1120°F), it is preheated electrically. On cars with TRIONIC, oxygen sensor preheating is controlled by the system's control module. In certain markets the system incorporates a relay which disconnects preheating when engine speed exceeds 3000 rpm because the exhaust gases then heat the oxygen sensor. The output signals weaken as the oxygen sensor ages and it must be changed after 160,000 km (100,000 miles).

Identifying Evaporative Emission System Diagram. Scheme 39

Function

Fuel vapours from the fuel tank ventilation system are carried to a canister filled with active charcoal where they are stored when the engine is not running.

When the car is driven the EVAP canister purge valve opens and the fuel vapours are then sucked into the engine and burned there.

The EVAP canister purge valve is controlled by the engine management system which takes the engine's workload, etc. into consideration and decides when the engine can burn this extra mixture.

Evaporative emission canister

The evaporative emission canister is filled with active charcoal whose purpose is to act as a "buffer store" for the fuel vapours from the fuel tank. These vapours are passed by the purge valve to the intake manifold for combustion together with the regular fuel-air mixture.

The evaporative emission canister is connected by hoses to the fuel tank and intake manifold. It is also in communication with the outside air. Outside air is sucked in through the evaporative emission canister where it is cleaned. On the way it absorbs the fuel vapours and carries them along with it to the intake manifold.

ORVR

To increase environmental safety still further and to meet legal requirements, an evaporative emission system for controlling hydrocarbon emissions in connection with refuelling has been developed. To meet these requirements, the car must deal with the evaporated hydrocarbons that are formed when filling up with fuel.

Only certain markets are equipped with this system.

All LEV cars (Low Emission Vehicle) are fitted with ORVR

The system is called Onboard Refueling Vapour Recovery (ORVR). It is described in "Evaporative emission system, ORVR".

The purpose of the deceleration device (not B235R) is to prevent the emission of unburned hydrocarbons during engine braking. It is integrated into the IAC valve.

IAC valve

The purpose of the IAC valve is to give

1. smoother engine running
2. better cold starting and warming-up performance
3. faster idling speed on engagement of the air conditioning system
4. compensation for drop in engine speed due to increased load from power steering pump and generator charging, and when driving at high altitudes
5. a deceleration function. The IAC valve controls the flow of air past the throttle valve. The volume of air is determined by the valve's degree of opening, which is governed by signals from the engine management system's control module. The necessary volume of air at any given moment can thus be admitted in order to maintain a constant idling speed. The IAC valve is a motorized slide valve supplied with power from a PWM output on the engine control module. The valve can move from closed to open position in less than 0.2 seconds. The movement is scarcely visible.

Removing Heat Shield Over Exhaust Manifold. Scheme 40

DO NOT allow the catalytic converter to hang from the flexible section.

Scheme 41

1. Remove the heat shield over the exhaust manifold.
2. Unplug the oxygen sensor's leads, undo the clip and cable clamps. IMPORTANT: The leads must not be twisted. The oxygen sensor is sensitive to knocks and blows and must be handled with care.
3. Unscrew the upper nuts at the joint between exhaust manifold and front exhaust pipe. Raise the car.
4. Remove the oxygen sensor. (Scheme 41): Removing Oxygen Sensor
5. Loosen the joint between the front exhaust pipe and the middle pipe.
6. Undo the remaining nuts at the joint between the front exhaust pipe and exhaust manifold. see scheme 13: Removing Nuts At Joint Between Front Exhaust Pipe & Exhaust Manifold
7. Remove the two rubber mountings between the catalytic converter and engine subframe
8. Lower the front exhaust pipe.

Fitting Rubber Mountings Between Catalytic Converter & Engine Subframe. Scheme 42

DO NOT allow the catalytic converter to hang from the flexible section.

Scheme 43

1. Clean the joints.
2. Fit the rubber mountings between the catalytic converter and engine subframe. If necessary, change the rubber bushes.
3. Position the front exhaust pipe and secure it to the exhaust manifold by means of the two lower nuts. Tightening torque: 40 Nm (30 lbf ft)
4. Bolt the front exhaust pipe and intermediate pipe together, using a new clamp. (Scheme 43): Installing Front Exhaust Pipe & Intermediate Pipe Together Tightening torque: 20 Nm (15 lbf ft) IMPORTANT: To avoid leakage, use new clamps when tightening the joints. Make sure that there is adequate clearance to parts next to the exhaust system. Also check that the rear silencer's tailpipe is correctly positioned in the opening that is cut out for it in the rear bumper.
5. Fit the oxygen sensor, but first lubricate the threads with Molycote 1000, part No. 30 20 971. Tightening torque: 55 Nm (41 lbf ft) IMPORTANT: The oxygen sensor is sensitive to knocks and blows and must be handled with care. It is important to ensure that the connection between it and the nipple is gastight. The oxygen sensor's lead must not be stretched between engine and exhaust pipe. Secure the cable to the clips so that a loop is formed just before the sensor.
6. Lower the car to the floor. see scheme 16: Plugging In Oxygen Sensor's Leads
7. Screw on the upper nuts securing the front exhaust pipe to the exhaust manifold and tighten them.
8. Plug in the oxygen sensor's leads and fit the clip and cable clamps.
9. Fit the heat shield over the exhaust manifold.

Removing Heat Shield Over Exhaust Manifold. Scheme 44

DO NOT allow the catalytic converter to hang from the bellows.

1. Remove the heat shield over the exhaust manifold.
2. Unplug the oxygen sensor's leads, undo the clip and the upper cable clamp. IMPORTANT: The leads must not be twisted. The oxygen sensor is sensitive to knocks and blows and must be handled with care.
3. Remove the lower cable clamp and oxygen sensor. Raise the car.
4. Loosen the joint between the front exhaust pipe and the middle pipe. see scheme 18: Loosening Joint Between Front Exhaust Pipe & Middle Pipe
5. Unscrew the front exhaust pipe from the turbocharger.
6. Detach the exhaust pipe from the rubber mounting on the engine subframe and lower the exhaust pipe.

Positioning & Securing Front Exhaust Pipe To Turbocharger. Scheme 45

1. Clean the joints.
2. Position the front exhaust pipe and secure it to the turbocharger. Before fitting, lubricate the three studs on the turbocharger with Molycote 1000, part No. 30 20 971. Tightening torque: 25 Nm (18.5 lbf ft)
3. Attach the exhaust pipe to the engine subframe with the rubber mountings from the catalytic converter. If necessary, use new rubber bushes.
4. Screw together the joint at the intermediate pipe, using a new clamp. Tightening torque: 20 Nm (15 lbf ft) IMPORTANT: To avoid leakage, use new clamps when tightening the joints.
5. Lower the car to the floor. (Scheme 46): Fitting Oxygen Sensor Fit the oxygen sensor, but first lubricate the threads with Molycote 1000, part No. 30 20 971. Tightening torque: 55 Nm (41 lbf ft) IMPORTANT: The oxygen sensor is sensitive to knocks and blows and must be handled with care. It is important to ensure that the connection between it and the nipple is gastight. The oxygen sensor's lead must not be stretched between engine and exhaust pipe. Secure the cable to the clips so that a loop is formed just before the sensor.
6. Run the cable up, connect it and fit the connector in the holder. IMPORTANT: Watch out for sharp edges and hot components. Secure the cable to the turbo's coolant pipe, using a cable tie.
7. Fit the heat shield over the exhaust manifold.

Dismantling

When changing the front exhaust pipe, the oxygen sensors must be removed and fitted to the new exhaust pipe. Apply Molykote 1000, part no. 30 20 971 to the threads on the oxygen sensors before fitting.

Since the oxygen sensors are sensitive to impact and shock, they must be handled with care.

1. Tightening torque: 55 Nm ( lbf ft)

Scheme 46

Scheme 47

1. Remove the bypass pipe with valve. Keep the O -ring where the pipe is connected to the turbo inlet pipe. (Scheme 47): Removing Bypass Pipe With Valve
2. Remove the exhaust manifold heat shield and the top engine cover.
3. Unplug the oxygen sensor connectors. Cut the cable tie securing the oxygen sensor cables and adjust their position so that they run free when the pipe is removed.
4. Undo the 2 upper nuts on the joint between the turbocharger and the front exhaust pipe. (Scheme 48): Removing Upper Nuts On Joint
5. Raise the car.
6. Undo the lower nut on the joint between the turbocharger and the front exhaust pipe as well as the bolt on the catalytic converter brace.
7. Remove the clamp at the joint between the front exhaust pipe and the intermediate pipe.
8. Unhook the exhaust pipe from its rubber mountings and lower it away. Make sure that the leads of the oxygen sensors are not caught up or damaged when the exhaust pipe is removed. IMPORTANT: The flexible section in the front part of the exhaust pipe must not be bent more than 5°.

To Fit

Scheme 48

Scheme 49

1. Clean the joints. (Scheme 49): Lifting Up & Hooking Exhaust Pipe To Rubber Mountings
2. Offer up the exhaust pipe and hook it onto its rubber mountings. If necessary, change the rubber bushes.
3. Fit the lower nut between the front exhaust pipe and the turbocharger. Smear the threads with Molycote 1000, part no. 30 20 971, or the equivalent. Tightening torque: 25 Nm (19 lbf ft)
4. Bolt the front exhaust pipe and intermediate pipe together, using a new clamp. Tightening torque: 30 Nm (22 lbf ft) IMPORTANT: To avoid leakage, use new clamps when tightening the joints. Make sure that there is adequate clearance to parts next to the exhaust system. Check that the tailpipe is positioned symmetrically in the space cut out for it in the rear bumper.
5. Fit the catalytic converter brace and oxygen sensor cables. Lower the car.
6. Fit the upper nuts between the front exhaust pipe and the turbocharger. Coat the threads with Molycote 1000, part no. 30 20 971, or the equivalent. Tightening torque: 25 Nm (19 lbf ft) IMPORTANT: Tighten the nuts alternately to avoid misalignment of the flange. The exhaust pipe flange must not abut against the turbocharger flange.
7. Run the oxygen cables forward and plug in the connector. Secure the cables with a cable tie. see scheme 24: Running Oxygen Cables Forward & Plugging Connector IMPORTANT: The oxygen sensor's leads must not be twisted. Make sure that the lead does not rest against hot surfaces or sharp edges.
8. Fit the exhaust manifold's heat shield.
9. Fit the bypass pipe with valve. Lubricate the O-ring at the connection to the turbo inlet pipe with non -acidic vaseline, part no. 30 06 665, or the equivalent.
10. Fit the top engine cover

Unplugging The Oxygen Sensor's Leads. Scheme 50

1. Unplug the oxygen sensor's leads, undo the cable clamps and clip. Raise the car. IMPORTANT: The leads must not be twisted. The oxygen sensor is highly sensitive to knocks and blows and must be handled with care.
2. Remove the oxygen sensor. see scheme 26: Removing Oxygen Sensor

Installing Oxygen Sensor. Scheme 51

1. Coat the oxygen sensor's threads with Molycote 1000 (30 20 971) to prevent binding. IMPORTANT: The oxygen sensor is sensitive to knocks and blows and must be handled with care. It is important to ensure that the connection between it and the nipple is gastight. The oxygen sensor's lead must not be stretched between engine and exhaust pipe. Secure the cable to the clips so that a loop is formed just before the sensor.
2. Fit the oxygen sensor. Tightening torque: 55 Nm (41 lbf ft)
3. Lower the car to the floor, plug in the leads and fit the cable clamps and clip. see scheme 28: Plugging In Leads And Fitting Cable Clamps & Clip

Opening Bonnet. Scheme 52

1. Open the bonnet.
2. Remove the cover over the throttle body.
3. Unplug the oxygen sensor's connector and remove it from the holder.
4. Snip the cable tie and withdraw the oxygen sensor's lead.
5. Remove the oxygen sensor. IMPORTANT: The leads must not be twisted. The oxygen sensor is highly sensitive to knocks and blows and must be handled with care.

Fitting Oxygen Sensor. Scheme 53

1. Coat the oxygen sensor's threads with Molycote 1000 (30 20 971) to prevent binding. IMPORTANT: The oxygen sensor is sensitive to knocks and blows and must be handled with care. It is important to ensure that the connection between it and the nipple is gastight. The oxygen sensor's lead must not be stretched between engine and exhaust pipe. Secure the cable to the clips so that a loop is formed just before the sensor.
2. Fit the oxygen sensor. Tightening torque: 55 Nm (41 lbf ft)
3. Run the cable up, connect it and fit the connector in the holder. IMPORTANT: Watch out for sharp edges, hot components, etc.
4. Secure the cable to the turbo's coolant pipe, using a cable tie.
5. Fit the cover over the throttle body and close the bonnet.

Scheme 54

1. Remove the top engine cover. (Scheme 54): Removing Top Engine Cover
2. Detach the connector from the holder.
3. Cut the cable tie and pull out the cable. (Scheme 55): Cutting Cable Tie & Pulling Out Cable
4. Raise the car.
5. Pull down the cable and remove the oxygen sensor. IMPORTANT: The leads must not be twisted. The oxygen sensor is highly sensitive to knocks and blows and must be handled with care.

Scheme 55

Scheme 56

1. Coat the oxygen sensor's threads with Molycote 1000 (30 20 971) to prevent binding. IMPORTANT: The oxygen sensor is sensitive to knocks and blows and must be handled with care. It is important to ensure that the connection between it and the nipple is gastight. IMPORTANT: Chemicals such as contact spray and grease must not come into contact with the oxygen sensor connectors.
2. Fit the oxygen sensor. Tightening torque: 55 Nm (41 lbf ft) (Scheme 56): Fitting Oxygen Sensor
3. Run the cable as far up as possible. Lower the car. IMPORTANT: Watch out for sharp edges, hot components, etc.
4. Run the cable forward and plug in the connector. (Scheme 57): Running Cable Forward & Plugging Connector
5. Secure the cable to the water pipe with a cable tie.
6. Fit the top engine cover.

Scheme 57

Scheme 58

1. Remove the top engine cover (Scheme 58): Removing Top Engine Cover
2. Detach the oxygen sensor connector from the holder.
3. Remove the bypass pipe and heat shield. (Scheme 59): Removing Bypass Pipe & Heat Shield
4. Cut the cable tie for the oxygen sensor and pull out the cables IMPORTANT: The leads must not be twisted. The oxygen sensor is highly sensitive to knocks and blows and must be handled with care.
5. Release the oxygen sensor from the turbo outlet pipe

Scheme 59

Scheme 60

1. Coat the oxygen sensor's threads with Molycote 1000 (30 20 971) to prevent binding. IMPORTANT: The oxygen sensor is sensitive to knocks and blows and must be handled with care. It is important to ensure that the connection between it and the nipple is gastight. IMPORTANT: Chemicals such as contact spray and grease must not come into contact with the oxygen sensor connectors.
2. Fit the oxygen sensor. Tightening torque: 55 Nm (41 lbf ft) (Scheme 60): Fitting Oxygen Sensor
3. Run the cable forward and plug in the connector. see scheme 38: Running Cable Forward & Plugging Connector
4. Secure the cable to the water pipe with a cable tie.
5. Fit the heat shield and bypass pipe.
6. Fit the top engine cover.

Detaching Intake Hose. Scheme 61

1. Detach the intake hose and unplug the valve's connector. IMPORTANT: Note the position of the valve.
2. Detach the hoses from the valve and remove the valve.

Fitting Valve & Hoses. Scheme 62

1. Fit the valve and fit the hoses. Remember to fit the valve the right way round.
2. Plug in the valve's connector and fit the intake hose.

1. Unplug the connector from the EVAP canister purge valve. Note the positioning of the purge valve. see scheme 41: Unplugging Connector From EVAP Canister Purge Valve
2. Remove the valve from the holder.
3. Detach the hoses.

Fitting Hoses. Scheme 63

Note. Spray the connector with Kontakt 61 (part no. 30 04 520).

1. Fit the hoses.
2. Fit the valve to the holder.
3. Plug the connector into the EVAP canister purge valve.