2002-2005 Nissan 350Z Stillen Headers Installation Instructions

Installation:
1. Start install by raising vehicle to a suitable working height. Observe proper safety precautions when working under vehicle.
2. Disconnect negative terminal of battery. Remove the air inlet tube and airbox from the driver’s side of vehicle. On the passenger side move any brackets and/or harnesses that may interfere with access to the manifold bolts or heat shields.
3. Remove the lower splashguard from the vehicle. Remove the 4 nuts securing the ‘Y’ pipe to the back of the catalytic converters. Note: Nissan recommends that all locking nuts and gaskets be replaced after removal.
4. Carefully disconnect the secondary O2 sensors from the catalytic converters. Disconnect the brace that goes from catalytic converters to the center of the transmission. Remove the 3 nuts from the top flanges of the converters and remove the converters from the car Figure 1. Note: the nuts facing upward are more easily accessible from the engine compartment with a long extension.
5. Remove the steering coupler Figure 2 from the steering shaft. Note: make sure the steering shaft does not turn when disconnected. If shaft is turned 360 degrees VDC/ traction control will not operate properly.
6. Remove the four 6mm bolts securing the right side heat shield. Remove the heat shield through the bottom of the vehicle. Repeat for the left side. Both shields will be a tight fit during removal, some patience is required. These shields will not be reused.
7. Disconnect the primary O2 sensors from the factory manifolds. Try not to twist the wiring or impact the sensors in any way. They are quite sensitive and may be damaged with rough handling.
8. Remove the six 10MM nuts (per side) that secure the left and the right manifolds to the cylinder heads. Both manifolds will be removed from underneath the vehicle.
9. Install manifold gaskets. Install the new Stillen headers from beneath the car. Caution should be taken when installing the right hand (passenger) side to avoid damaging the fuel line Figure 3
10. Apply anti-seize to all studs and install 6 attaching nuts to each of the exhaust manifolds. Torque these nuts to 21-23 ft-lbs.

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