Exhaust Manifold: Service and Repair

Removal and Installation

EM-26 Component:

REMOVAL

WARNING: Perform the work when the exhaust and cooling system have completely cooled down.

1. Remove engine room cover (RH and LH).
2. Remove engine cover with power tool.
3. Remove air cleaner case and air duct.
4. Remove front and rear engine undercover with power tool.
5. Remove exhaust front tube and three way catalysts (right bank and left bank).
6. Disconnect air fuel ratio sensor 1 (right bank and left bank) harness connectors and remove harness clip.





7. Using the heated oxygen sensor wrench (SST), remove air fuel ratio sensor 1 (right bank and left bank).

CAUTION:
^ Be careful not to damage air fuel ratio sensor 1.
^ Discard any air fuel ratio sensor 1 which has been dropped onto a hard surface such as a concrete floor, replace with a new sensor.

8. Remove exhaust manifold cover (right bank and left bank).





9. Loosen mounting nuts in the reverse order as shown in the figure to remove exhaust manifold with power tool.

NOTE: Disregard the numerical order No. 7 and 8 in removal.

10. Remove gaskets.

CAUTION: Cover engine openings to avoid entry of foreign materials.

INSPECTION AFTER REMOVAL

Surface Distortion





^ Check the surface distortion of the exhaust manifold mating surface with a straightedge and a feeler gauge.
Limit: 0.3 mm (0.012 in)
^ If it exceeds the limit, replace exhaust manifold.

INSTALLATION
Note the following, and install in the reverse order of removal.

Exhaust Manifold Gasket





^ Install exhaust manifold gasket in direction shown in the figure. (Follow same procedure for both banks.)
A: Right bank
B: Triangle press
C: Left bank
<---: Engine front

Exhaust Manifold
^ If stud bolts were removed, install them and tighten to the specified torque below.
Tightening torque: 14.7 Nm (1.5 kg-m, 11 ft-lb)





^ Install exhaust manifold and tighten mounting bolts in numerical order as shown in the figure.

NOTE: Tighten nuts No. 1 and 2 in two steps. The numerical order No. 7 and 8 shows second step.

Air Fuel Ratio Sensor

CAUTION:
^ Before installing a new air fuel ratio sensor, clean exhaust system threads using heated oxygen sensor thread cleaner tool (commercial service tool: J-43897-18 or J-43897-12) and apply anti-seize lubricant (commercial service tool).
^ Never over torque air fuel ratio sensor. Doing so may cause damage to air fuel ratio sensor, resulting in the "MIL" coming on.