Exhaust Manifold: Service and Repair

EXHAUST MANIFOLD AND THREE WAY CATALYST

Image Symbols:

Removal and Installation
REMOVAL

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

1. Remove engine cover with power tool.
2. Remove front and rear engine undercover with power tool.
3. Remove air duct (inlet), air cleaner case and mass air flow sensor assembly, air duct and resonator assembly.
4. Remove front cross bar.
5. Drain engine coolant from radiator.

CAUTION:
^ Perform this step when engine is cold.
^ Do not spill engine coolant on drive belts.

6. Remove radiator.
7. Remove drive belts.
8. Remove air fuel ratio sensor 1 and heated oxygen sensor 2 as follows:
a. Disconnect air fuel ratio sensor 1 and heated oxygen sensor 2 harness connectors.








b. Remove air fuel ratio sensor 1 and heated oxygen sensor 2 on both bank with heated oxygen sensor wrench (SST).

CAUTION:
^ Be careful not to damage air fuel ratio sensor 1 and heated oxygen sensor 2.
^ Discard any air fuel ratio sensor 1 and heated oxygen sensor 2 which have been dropped onto a hard surface such as a concrete floor; replace with a new one.

9. Remove exhaust mounting bracket between three way catalysts (right and left bank) and transmission.
10. Disconnect A/C piping from A/C compressor, then remove A/C compressor with power tool. Refer to ATC-139, Components. [1][2]Exploded Views
11. Remove alternator and bracket.
12. Remove exhaust front tube with power tool.
13. Remove steering lower joint at power steering gear assembly side, and release steering lower shaft.
14. Remove three way catalysts (right and left bank).
15. Remove exhaust manifold covers. (Right and left bank)





16. Loosen mounting nuts in reverse order as shown in the figure to remove exhaust manifold.
A: Left bank
B: Right bank

NOTE: Disregard the numerical order No. 9 to 12 in removal.

17. Remove exhaust manifold gaskets.

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

INSPECTION AFTER REMOVAL
Surface Distortion





^ Check the surface distortion of the each exhaust manifold flange mating surface with straightedge and feeler gauge.
Limit: 0.3 mm (0.012 inch)
^ 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 with its directional protrusion set upward. Refer to the figure of components.

Exhaust Manifold
^ Install exhaust manifold and tighten mounting nuts in numerical order as shown in the figure.
A Left bank
B Right bank
<-: Engine front

NOTE: Tighten mounting nuts No. 1 to 4 in two steps. The numerical order No. 9 to 12 shown second steps.

Air Fuel Ratio Sensor and Heated Oxygen Sensor
^ Install air fuel ratio sensors and heated oxygen sensors in the original position.





^ Install referring the following if the installation positions cannot be identified.
Glass tube color
Air fuel ratio sensor 1: Black
Heated oxygen sensor 2: White

CAUTION:
^ Before installing a new air fuel ratio sensor and heated oxygen sensor, clean exhaust system threads using oxygen sensor thread cleaner (commercial service tool: J-43897-18 or J-43897-12), and apply anti-seize lubricant (commercial service tool).
^ Do not over torque air fuel ratio sensor and heated oxygen sensor. Doing so may cause damage to the heated oxygen sensor, resulting in MIL coming on.