2008 Hummer H3 Alpha, 5.3L, 4wd Cat-Back Split Rear Exhaust Installation Instructions

2008 Hummer H3 Alpha, 5.3L, 4wd Cat-Back Split Rear Exhaust Installation Instructions

When installing this exhaust system make sure to use proper safety precautions. Use jack stands when working under the vehicle, set parking brake, block tires and use safety glasses and gloves. Allow exhaust to cool before attempting installation. Severe injury or burns could occur if safety measures are not taken.
SUGGESTED TOOLS: 1/2″, 9/16″, 15mm wrenches & sockets, WD-40, hacksaw, jack stands

1. Disconnect the negative battery cable before removal of OEM exhaust. This will allow the computer to reset and recognize the new exhaust. Lay out the exhaust on the floor so it looks like the drawing and compare parts with manual.
2. To remove the stock exhaust, cut just in front of the stock resonator. (see picture) Disengage the welded hangers from the OEM rubber grommets. Use WD-40 to aid in the process. Do not damage or remove the rubber grommets as they will be reused to mount the new system. Now, cut off tailpipe and remove exhaust.
3. Slide muffler #A onto headpipe 1―”-2”. Use a jack stand to support the muffler. Make sure muffler outlets are level. Use clamp #G to secure the muffler to the headpipe. Do not tighten.
4. Slide driver side over axle tailpipe #B into muffler 1.5-2”. Use clamp #F to secure tailpipe to muffler. Do not tighten. Insert welded hanger into rubber grommet.
5. Slide the second driver side over axle tailpipe #C onto pipe #B 1.5-2”. Secure pipes using clamp #F. Do not tighten. Insert welded hanger into rubber grommet.
6. Slide the passenger side tailpipe #D into muffler 1.5-2”. Insert welded hanger into rubber grommet. Use clamp #F to secure tailpipe to muffler. Do not tighten.
7. Install stainless steel tips. Clamp down. When you have everything in place, firmly tighten all bolts and clamps down securely. Use stainless steel or aluminum cleaner to polish tips. Inspect all fasteners after 25-50 miles of operation and re-tighten as necessary.