If you confirm that there is an exhaust rattle/buzzing noise that sounds like it’s coming from the front exhaust tube on an applied vehicle, take the following actions.

Actions:
1. Inspect both of the catalyst front tube support brackets for breaks, cracks or missing bolts.
2. If you determine that the support brackets need to be replaced:
• Replace both support brackets and bolts. It is not necessary to replace the front tube assembly.

Note: For vehicles equipped with a 5-speed automatic transmission, you will also install exhaust tube mounting brackets.

Important: The purpose of “Actions” is to give you a quick idea of the work you’ll be performing. You must closely follow the entire Service Procedure as it contains information that is essential to successfully completing the repair.

Applied Vehicles:
• 2004-’06 Maxima (A34);
• 2004-’07 Quest (V42); and
• 2003-’06 Murano (Z50).

Applied VINS:
• 2004-’06 Maxima, all VINs;
• 2004-’06 Quest, all VINs;
• 2007 Quest built before: 5N1BV*8U*7N136219;
• 2003-’05 Murano, all VINs; and
• 2006 Murano built before: JN8AZ08T*6W 402002 (2WD) or JN8AZO8W*6W 505916 (AWD).

Service Procedure:
1. Inspect both support brackets on the catalyst front tube. See Fig. 1. Brackets are located between the exhaust flange of Bank 1 catalyst and the transmission housing. Check for breaks or cracks, and loose or missing bolts.

Note: Breaks or cracks may be found anywhere on the bracket body or at the mounting bolt holes. Cracks appear in a “hairline” form. See Figures 2 and 3.

2. If either of the support brackets are broken/cracked, or have loose or missing bolts, replace both brackets and all their bolts as follows:

a. Remove the original bolts and brackets and discard.

b. If the vehicle is equipped with a 5-speed automatic transmission, install exhaust tube mounting brackets (upper and lower) and flange nuts. See Figures 4 and 5, and Fig. 6. Torque each nut to 30.4-39.2 Nm (3.1-4.0kg-m, 22.4-28.9 ft-lb).

c. Loosely install the new support brackets and bolts.

d. Position all brackets so that each bolt is centered in the bolt holes.

e. Hand-tighten each bolt to hold it in the centered position.

f. Torque each bolt to 19.0–25.0 Nm (1.93-2.43kg-m, 14-18.4 ft.-lb.), starting with the transmission side bolt.

3. Make sure the rattle/buzzing noise is gone. Conduct a short test drive involving several low speed part throttle accelerations.

Note: It is best to listen for unusual exhaust noise while driving with windows down and driving next to an object such as a wall, hedge or parked cars. Any unusual noises, if they exist, will reflect back to your car and are more noticeable.

Courtesy of Mitchell 1.

For more information on Mitchell 1 products and services, automotive professionals can log onto the company’s website at www.mitchell1.com.