Lumina L4-151 2.5L (1991)
Exhaust Manifold: Service and Repair
Fig. 3 Exhaust Manifold Tightening Sequence
1.
Remove air cleaner, then torque rod strut.
2.
Remove oxygen sensor connector, then dipstick tube.
3.
Raise and support vehicle, then remove exhaust pipe from manifold.
4.
Lower vehicle, then remove exhaust manifold attaching bolts and washers.
5.
Remove exhaust manifold and gasket.
6.
Reverse procedure to install, torquing exhaust manifold bolts 1,2,6 and 7 to 28 ft. lbs. and bolts 3,4 and 5 to 37 ft. lbs. in sequence shown in Fig.
3.
