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If a cracked right-hand exhaust manifold on a 1999-2001 Nissan VGS33E engine is discovered when the exhaustheat shield is removed, installers must replace the exhaust manifold.

If one of these symptoms should occur, use the following to diagnosethe condition, replacing the right-hand exhaust manifold and relatedparts as described.
 
SERVICE PROCEDURE

Diagnosis:

1. Installers should verify the source of the noise with the engine running that it is coming from the right-hand manifold area.
 
2. If the noise is coming from the right-hand manifold area, remove theheat shield and inspect for cracks between the #1 and #3 ports on themanifold.
 
Repair:

1. Separate the catalyst from the right-hand exhaust manifold and remove it to allow for clearance.
 
Caution: The nuts that attach the catalyst to the exhaust manifold havea self-locking design and require some effort to remove. Applypenetrating oil to the threads and allow it to soak in beforeattempting to remove the nuts.
 
Use a tight-fitting six-point socket to avoid rounding off the cornersof the nuts during removal. If any of the nuts or studs are damagedduring removal, replace them as needed.
 
2. Remove the exhaust manifold from the head (See Figure 2A for loosening sequence of manifold nuts). NOTE: If any of the nuts or studs are damaged during removal, replace them as needed.
 
3. Install the replacement manifold with a new gasket onto the head. See Figure 2B for tightening sequence of manifold nuts. See Figure 1 for manifold nut torque specifications.
 
4. Re-attach the catalyst to the exhaust manifold. NOTE: Ensure thatall bolts securing the manifold and heat shields are installed and aretorqued to the specifications shown in Figure 1.
 
5. Installers should test-drive the vehicle to verify the ticking or exhaust noise has been eliminated.

Some or all of this information was provided by the AutomotiveParts Remanufacturers Association (APRA). For more information ontechnical bulletins available through APRA call 703-968-2772 or visit www.AutoBulletins.com.figure 1figure 2aFigure 2B

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