PLUG AS 7I7555 - Caterpillar

Removal Procedure
Start By:
Remove radiator.
Remove air cooler.
Remove hydraulic oil cooler.
Remove DEF injector.
Illustration 1 g03874018
Disconnect harness assemblies (4). Remove bolts (1) and reposition sensors (2).Note: The two NOx sensors have different color coded cables. The outlet NOx temperature sensor is gray and the inlet NOx sensor is black. Mark harness assemblies (4) to ensure that they are installed to the correct NOx sensor during reassembly.
Remove bolts (5) and exhaust extension (3).
Illustration 2 g03874275
Disconnect harness assembly (6) for the Pre NOx sensor, Post NOx Sensor, and SCR Inlet Temperature Sensor.
Illustration 3 g03874298
Remove bolts (7) and bolts (8).
Illustration 4 g03874500
Use a suitable lifting device to remove catalyst assembly (10). The weight of catalyst assembly (10) is approximately ().
Remove bolts (9) and catalyst assembly (10).
Illustration 5 g03874645
Remove bolts (11) and brackets (12).
Illustration 6 g03874675
Remove clamp assembly (14) and pipe assembly (13).
Illustration 7 g03874689
Remove bolts (18) and engine lifting eye (17).
Remove bolt (19) and bracket (15).
Remove bolts (16), bolt (20), bolts (22), and bracket assembly (21).
Illustration 8 g03875070
Remove bolts (24) and bracket (25).
Remove nuts (26), bolt (27), and base bracket (23).
Illustration 9 g03875085
Remove bolt (29), bolt (30), nuts (31), and base bracket (28).Installation Procedure
Install catalyst assembly (10) in the reverse order of removal.
Tighten nuts (31), bolt (30), bolt (29), bolt (27), nuts (26) to a torque of 124 - 147 N m (91 - 108 lb ft).
Tighten bolts (22), bolts (20), bolt (19), bolts (16), and bolts (18) to a torque of 49 - 55 N m (36 - 41 lb ft).
Tighten clamp assembly (14) and clamp assembly (13) to a torque of 15 2 N m (133 18 lb in).
Tighten bolts (11), bolts (9), bolts (8), and bolts (7) to a torque of 49 - 55 N m (36 - 41 lb ft).