Crossover Pipe Replacement; Catalytic Converter Replacement - Hummer H1 Service Manual

3-44 Fuel, Emissions, and Exhaust

CROSSOVER PIPE REPLACEMENT

1. Remove console and engine cover.
2. Remove passenger side exhaust manifold rear heat shield.
3. Loosen transfer case exhaust pipe bracket U-bolt
(Figure 3-62).
4. Disconnect crossover pipe at manifolds and at catalytic
converter.
5. Position new crossover pipe on manifolds. Tighten flange
bolts to 26 lb-ft. (35 N•m).
6. Connect crossover pipe to catalytic converter and tighten
flange bolts to 26 lb-ft. (35 N•m).
7. Tighten exhaust bracket U-bolt nuts at transfer case to 26
lb-ft. (35 N•m).
8. Install heat shield.
9. Install engine cover and console.
10. Start and run engine. Verify that exhaust components are
clear of body, frame, and driveline parts.
U-BOLT
CROSSOVER-TO-CONVERTER PIPE
SUPPORT BRACKET
TRANSFER CASE
Figure 3-62: Transfer Case Exhaust Bracket
Mounting
4-1-00
___________________________________________
CLAMP

CATALYTIC CONVERTER REPLACEMENT

1. Loosen or remove necessary frame brackets and clamps
that retain converter and pipe (Figures 3-61 and 3-62).
2. Remove bolts attaching converter to crossover or head
pipe.
3. Remove flange bolts attaching converter to muffler and
crossover or head pipe.
4. Remove U-bolt at transfer case bracket.
5. Remove converter.
6. Position new single or dual converter assembly in vehicle
and loosely install flange bolts.
7. Connect necessary exhaust brackets and clamps to frame
or body as required.
8. Tighten exhaust flange bolts to 26 lb-ft. (35 N•m).
9. Tighten frame bracket bolts.
10. Tighten transfer case exhaust bracket U-bolt nuts to 26 lb-
ft. (35 N•m).
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