Exhaust Manifold and Three Way Catalyst Removal and Installation

Exhaust Manifold and Three Way Catalyst: Removal and Installation [QR25DE]

Removal

1) Disconnect harness connector of air fuel ratio sensor 1, and harness from bracket and middle clamp.
2) Remove air fuel ratio sensor 1 using Tool.






CAUTION:
- Be careful not to damage air fuel ratio sensor 1.
- Discard any air fuel ratio sensor 1 which has been dropped from a height of more than 0.5 m (19.7 in) onto a hard surface such as a concrete floor; replace with a new one.

3) Remove exhaust front tube. Refer to [Exhaust System: Exploded View] Exploded View.
4) Remove exhaust manifold cover.
5) Remove bracket between exhaust manifold-three way catalyst assembly and transmission assembly.
6) Loosen nuts in reverse order as shown to remove exhaust manifold and three way catalyst assembly.





7) Remove gasket.

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

Inspection after Removal

Surface Distortion

- Check the surface distortion of exhaust manifold and three way catalyst assembly mating surface with straightedge and feeler gauge.











- If it exceeds the limit, replace exhaust manifold and three way catalyst assembly.

Installation

installation is in the reverse order of removal.

Exhaust Manifold

1) If stud bolts were removed, install them and tighten to the specified torque.






2) Tighten nuts in numerical order as shown.





3) Tighten nuts in numerical order as shown again.

Air Fuel Ratio Sensor 1

CAUTION:

- Do not over tighten air fuel ratio sensor 1. Doing so may cause damage to air fuel ratio sensor 1, resulting in the "MIL" coming on.
- Before installing new air fuel ratio sensor 1, clean exhaust system threads using suitable tool and apply anti-seize lubricant.