Exhaust System (h4dotc) Subaru Impreza WRX GD/GG рестайлинг

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CAUTION

1. Wear working clothing, including a cap, protective goggles, and protective shoes during operation.
2. Remove contamination including dirt and corrosion before removal, installation or disassembly.
3. Keep the disassembled parts in order and protect them from dust or dirt.
4. Before removal, installation or disassembly, be sure to clarify the failure. Avoid unnecessary removal, installation, disassembly, and replacement.
5. Be careful not to burn your hands, because each part on the vehicle is hot after running.
6. Be sure to tighten fasteners including bolts and nuts to the specified torque.
7. Place shop jacks or safety stands at the specified points.
8. Before disconnecting electrical connectors of sensors or units, be sure to disconnect the negative terminal from battery.

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1. Disconnect the ground terminal from battery.
2. Remove the front oxygen (A/F) sensor, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/exhaust/#exhaust-system-h4dotc) , Front Oxygen (A/F) Sensor.
3. Remove the under cover.
4. Remove the lower exhaust manifold cover (RH).
5. Remove the lower and upper exhaust manifold covers (LH).
6. Remove the bolts and nuts which hold the front exhaust pipe assembly to turbocharger joint pipe.
7. While holding the front exhaust pipe assembly with one hand, remove the nuts which hold the front exhaust pipe assembly to cylinder head exhaust port.
8. Remove the front exhaust pipe assembly.
9. Remove the covers from exhaust manifold and front exhaust pipe.
10. Separate the front exhaust pipe from exhaust manifolds.

INSTALLATION

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1. Assemble the front exhaust pipe and exhaust manifolds. Tightening torque: 35 N.m (3.6 kgf-m, 26.0 ft-lb)
2. Install the front exhaust pipe covers. Tightening torque: 25 N.m (2.5 kgf-m, 18.1 ft-lb)
3. Install the upper exhaust manifold cover (RH). Tightening torque: 19 N.m (1.9 kgf-m, 13.7 ft-lb)
4. Install the front exhaust pipe assembly. Tightening torque: 35 N.m (3.6 kgf-m, 26.0 ft-lb)
5. Connect the exhaust manifold (RH) to turbocharger joint pipe. Tightening torque: 35 N.m (3.6 kgf-m, 26.0 ft-lb)
6. Install the upper and lower exhaust manifold covers (LH). Tightening torque: 19 N.m (1.9 kgf-m, 13.7 ft-lb)
7. Install the lower exhaust manifold cover (RH). Tightening torque: 19 N.m (1.9 kgf-m, 13.7 ft-lb)
8. Install the front oxygen (A/F) sensor, see «INSTALLATION»(/subaru/impreza-wrx/gdgg-2002-2005/remont/exhaust/#exhaust-system-h4dotc) , Front Oxygen (A/F) Sensor. Tightening torque: 21 N.m (2.1 kgf-m, 15.2 ft-lb)
9. Install the under cover.
10. Connect the battery ground terminal to battery.

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1. Set the vehicle on the lift.
2. Disconnect the ground terminal from battery.
3. Remove the intercooler. See «INTERCOOLER (CHARGE AIR COOLER)»(/subaru/impreza-wrx/gdgg-2002-2005/remont/removal-installation/#engine-controls-removal-installation-impreza-outback-sport) .
4. Remove the intercooler bracket.
5. Lift-up the vehicle.
6. Remove the under cover.
7. Remove the bolts which install the lower side of turbocharger upper cover. CAUTION: Be careful, the turbocharger and exhaust pipe are hot.
8. Lower the vehicle.
9. Remove the turbocharger upper cover.
10. Remove the bolts which install the lower upper side of turbocharger upper cover, and remove it.
11. Separate the center exhaust pipe from turbocharger.
12. Lift-up the vehicle.
13. Disconnect the connector from rear oxygen sensor.
14. Vertically draw out clip from crossmember.
15. Separate the center exhaust pipe from rear exhaust pipe.
16. Remove the bolt which holds center exhaust pipe bracket to transmission.
17. Remove the intercooler bracket.
18. Remove the bolt which holds center exhaust pipe to hanger bracket. CAUTION: Be careful not to pull down the center exhaust pipe.
19. Remove the center exhaust pipe.

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1. Install the center exhaust pipe and temporarily tighten the bolt which holds center exhaust pipe to hanger bracket.
2. Temporarily tighten the bolt which holds the center pipe to transmission.
3. Connect the center exhaust pipe to turbocharger. Tightening torque: 35 N.m (3.6 kgf-m, 26.0 ft-lb)
4. Install the center exhaust pipe to rear exhaust pipe. Tightening torque: 18 N.m (1.8 kgf-m, 13.0 ft-lb)
5. Connect the connector to rear oxygen sensor.
6. Secure clip on the crossmember.
7. Tighten the bolt which holds the center exhaust pipe bracket to transmission. Tightening torque: 30 N.m (3.1 kgf-m, 22.4 ft-lb)
8. Tighten the bolt which holds the center exhaust pipe to hanger bracket. Tightening torque: 35 N.m (3.6 kgf-m, 26.0 ft-lb)
9. Tighten the bolts which hold the intercooler bracket. Tightening torque: 35 N.m (3.6 kgf-m, 26.0 ft-lb)
10. Lower the vehicle.
11. Place the turbocharger lower cover, and tighten the bolts which install the upper side of lower cover. Tightening torque: 7.4 N.m (0.75 kgf-m, 5.4 ft-lb)
12. Place the turbocharger upper cover, and tighten the bolts which install the upper side of upper cover. Tightening torque: 7.4 N.m (0.75 kgf-m, 5.4 ft-lb)
13. Lift-up the vehicle.
14. Tighten the bolts which install the under side of turbocharger upper cover. Tightening torque: 7.4 N.m (0.75 kgf-m, 5.4 ft-lb)
15. Install the under cover.
16. Lower the vehicle.
17. Install the intercooler bracket.
18. Install the intercooler. See «INTERCOOLER (CHARGE AIR COOLER)»(/subaru/impreza-wrx/gdgg-2002-2005/remont/removal-installation/#engine-controls-removal-installation-impreza-outback-sport) .

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1. Disconnect the ground terminal from battery.
2. Remove the solenoid valve cover.
3. Disconnect the exhaust temperature sensor connector.
4. Remove the front oxygen (A/F) sensor, see «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/exhaust/#exhaust-system-h4dotc) , Front Oxygen (A/F) Sensor.
5. Remove the under cover.
6. Remove the lower exhaust manifold cover (RH).
7. Remove the nuts which hold the front exhaust manifold to joint pipe.
8. Remove the center exhaust pipe. See «REMOVAL»(/subaru/impreza-wrx/gdgg-2002-2005/remont/exhaust/#exhaust-system-h4dotc) , Center Exhaust Pipe.
9. Remove the turbocharger. See «TURBOCHARGER»(/subaru/impreza-wrx/gdgg-2002-2005/remont/removal-installation/#engine-controls-removal-installation-impreza-outback-sport) .
10. Take off the joint pipe in the upward direction.

Install in the reverse order of removal.

Tightening torque

1. T: 35 N.m (3.6 kgf-m, 26.0 ft-lb)

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1. Disconnect the ground terminal from battery.
2. Lift up the vehicle.
3. Separate the rear exhaust pipe from center exhaust pipe. CAUTION: Be careful, the exhaust pipe is hot.
4. Separate the rear exhaust pipe from muffler. CAUTION: Be careful not to pull down the rear exhaust pipe.
5. Remove the rear exhaust pipe.

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1. Install the rear exhaust pipe to muffler. Tightening torque: 48 N.m (4.9 kgf-m, 35.4 ft-lb)
2. Install the rear exhaust pipe to center exhaust pipe. Tightening torque: 18 N.m (1.8 kgf-m, 13.0 ft-lb)
3. Lower the vehicle.
4. Connect the battery ground terminal to battery.

INSPECTION

1. Make sure there are no exhaust leaks from connections and welds.
2. Make sure there are no holes or rusting.
3. Make sure the cushion rubber is not worn or cracked.

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1. Separate the muffler from rear exhaust pipe. CAUTION: Be careful, the exhaust pipe may be hot.
2. Remove the rubber cushions, and detach muffler.

Note. To facilitate removal, apply a coat of SUBARU CRC to the mating area of rubber cushions in advance.

SUBARU CRC (Part No. 004301003)

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1. Install in the reverse order of removal. CAUTION: Replace the gasket with a new one. Tightening torque: 48 N.m (4.9 kgf-m, 35.4 ft-lb)

1. Make sure there are no exhaust leaks from connections and welds.
2. Make sure there are no holes or rusting.
3. Make sure the cushion rubber is not worn or cracked.

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1. Disconnect the battery ground cable.
2. Remove the solenoid valve cover.
3. Disconnect the connector from the front oxygen (A/F) sensor.
4. Disconnect the engine harness fixed by clip (A) from the bracket (B).
5. Remove the front right side wheel.
6. Lift-up the vehicle.
7. Remove the service hole cover.
8. Apply SUBARU CRC or its equivalent to the threaded portion of front oxygen (A/F) sensor, and leave it for one minute or more. SUBARU CRC (Part No. 004301003)
9. Remove the front oxygen (A/F) sensor. CAUTION: When removing the oxygen (A/F) sensor, wait until exhaust pipe cools, otherwise it will damage exhaust pipe.

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1. Before installing front oxygen (A/F) sensor, apply the anti-seize compound only to the threaded portion of front oxygen (A/F) sensor to make the next removal easier. Anti-seize compound: SS-30 by JET LUBE CAUTION: Never apply anti-seize compound to protector of front oxygen (A/F) sensor.
2. Install the front oxygen (A/F) sensor. Tightening torque: 21N.m (2.1 kgf-m, 15.2 ft-lb)
3. Install the service hole cover.
4. Lower the vehicle.
5. Install the front right side wheel.
6. Connect the engine harness with clip (A) to the bracket (B).
7. Connect the connector of front oxygen (A/F) sensor.
8. Install the solenoid valve cover.
9. Connect the battery ground cable.

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1. Disconnect the battery ground cable.
2. Lift-up the vehicle.
3. Disconnect the connector from the rear oxygen sensor.
4. Remove the clip by pulling out from the upper side of crossmember.
5. Apply SUBARU CRC or its equivalent to the threaded portion of rear oxygen sensor, and leave it for one minute or more. SUBARU CRC (Part No. 004301003)
6. Remove the rear oxygen sensor. CAUTION: When removing the oxygen sensor, wait until exhaust pipe cools, otherwise it will damage exhaust pipe.

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1. Before installing rear oxygen sensor, apply the anti-seize compound only to the threaded portion of rear oxygen sensor to make the next removal easier. CAUTION: Never apply anti-seize compound to protector of rear oxygen sensor. Anti-seize compound: SS-30 by JET LUBE
2. Install the rear oxygen sensor. Tightening torque: 21 N.m (2.1 kgf-m, 15.2 ft-lb)
3. Connect the connector to the rear oxygen sensor.
4. Connect the clip to the crossmember.
5. Lower the vehicle.
6. Connect the battery ground cable.

See also:
• INTERCOOLER (CHARGE AIR COOLER)
• REMOVAL