Nope.
The exhaust manifold needs to have a gasket in place to help seal the juncture between the manifold and the engine. After the gasket and gasket sealer are in place, tighten the bolts for the exhaust manifold. The exhaust pipe can then be replaced on the new exhaust manifold.
You will need to remove the exhaust manifold retaining bolts in your 1993 Chevy Astro. Remove the exhaust manifold. Remove the exhaust manifold gasket and clean the surface. Reverse the process to install the new exhaust manifold gasket.
40 lbs
Exhaust Manifold Removal & Installation 4.6L, 5.4L and 6.8L Engines 1. Raise and safely support the vehicle. 2. Remove the front fender splash shield. 3. For the left-hand exhaust manifold, remove the EGR valve-to-exhaust manifold tube and disconnect the Differential Pressure Feedback Exhaust [DPFE] gas recirculation transducer hoses. 4. Remove the oil stick from the engine. 5. On the 4.6L and 5.4L engines, remove the catalytic converter-to-exhaust manifold bolts. On the 6.8L engine, remove the front exhaust pipe from the manifold. 6. Remove the exhaust manifold mounting nuts, then remove the exhaust manifold itself. 7. Remove and discard the old gasket. 8. Clean and inspect the exhaust manifold for damage. To install: 9. Position a new gasket and the exhaust manifold onto the engine block. 10. Install the mounting nuts and tighten, in the sequence shown, to 13-16 ft.lbs. [18-22 Nm] on the 4.6L and 5.4L engines. Tighten the nuts to 17-20 ft.lbs. [23-27 Nm] on the 6.8L engine. {Tighten the passenger side exhaust manifold bolts in the order shown-4.6L and 5.4L engines} Kriss x kross 11. On the 6.8L engine, tighten the exhaust manifold-to-front pipe fasteners to 27-34 ft.lbs. [34-46 Nm]. 12. On the 4.6L and 5.4L engines, attach the catalytic converter to the exhaust manifold, then install the catalytic converter-to-exhaust manifold bolts and tighten to 25-34 ft. lbs. [34-46 Nm]. 13. Install the oil stick. 14. For the left-hand exhaust manifold, install the PDFE transducer hoses if equipped, and EGR-to-exhaust manifold tube. Tighten the upper and lower fitting to 26-33 lbs. [35-45 Nm]. 15. Install the front fender splash shield. 16. Lower the vehicle to the ground.
What engine???????? You should refer to repair manual if not familiar with auto repair and understand the terminology before attempting Remove nuts holding exhaust manifold to cylinder head & remove nuts/bolts holding exhaust manifold to exhaust pipes Use new exhaust manifold gaskets and install the new manifold securing the manifold to cylinder head (may need to but new nuts and or bolts) by "snugly" tightening manifold to cylinder head if not refering to repair manual
Exhaust Manifold Removal & Installation 4.6L, 5.4L and 6.8L Engines 1. Raise and safely support the vehicle. 2. Remove the front fender splash shield. 3. For the left-hand exhaust manifold, remove the EGR valve-to-exhaust manifold tube and disconnect the Differential Pressure Feedback Exhaust [DPFE] gas recirculation transducer hoses. 4. Remove the oil stick from the engine. 5. On the 4.6L and 5.4L engines, remove the catalytic converter-to-exhaust manifold bolts. On the 6.8L engine, remove the front exhaust pipe from the manifold. 6. Remove the exhaust manifold mounting nuts, then remove the exhaust manifold itself. 7. Remove and discard the old gasket. 8. Clean and inspect the exhaust manifold for damage. To install: 9. Position a new gasket and the exhaust manifold onto the engine block. 10. Install the mounting nuts and tighten, in the sequence shown, to 13-16 ft.lbs. [18-22 Nm] on the 4.6L and 5.4L engines. Tighten the nuts to 17-20 ft.lbs. [23-27 Nm] on the 6.8L engine. {Tighten the passenger side exhaust manifold bolts in the order shown-4.6L and 5.4L engines} Kriss x kross 11. On the 6.8L engine, tighten the exhaust manifold-to-front pipe fasteners to 27-34 ft.lbs. [34-46 Nm]. 12. On the 4.6L and 5.4L engines, attach the catalytic converter to the exhaust manifold, then install the catalytic converter-to-exhaust manifold bolts and tighten to 25-34 ft. lbs. [34-46 Nm]. 13. Install the oil stick. 14. For the left-hand exhaust manifold, install the PDFE transducer hoses if equipped, and EGR-to-exhaust manifold tube. Tighten the upper and lower fitting to 26-33 lbs. [35-45 Nm]. 15. Install the front fender splash shield. 16. Lower the vehicle to the ground.
Most oxygen sensors are located on the exhaust manifold or just after the manifold on the exhaust pipe(s). Your truck probably has two oxygen sensors, one on each side.
you will have to unbolt the exhaust pipe from the manifold pipe and then you unbolt the manifold pipe from the engine, remove old gasket and make sure both sides are clean of the old gasket and then install new gasket and bolt manifold back onto engine.
Follow the manual (Haynes, Chilton, Ford Factory). After the old manifold is off, clean the mating surfaces. Install a new gasket (no cement). Bolt on the new manifold. Tighten the bolts and nuts to the torque specs in the manual following the procedure in the manual. Bolt it to the exhaust pipe (new gasket also).
Follow the manual (Haynes, Chilton, Ford Factory). After the old manifold is off, clean the mating surfaces. Install a new gasket (no cement). Bolt on the new manifold. Tighten the bolts and nuts to the torque specs in the manual following the procedure in the manual. Bolt it to the exhaust pipe (new gasket also).
install a new one!!
Remove the intake manifold, exhaust manifold, and then remove the head. Scrap off the old gasket and install a new one. Reinstall the head and Torque the head bolts in the proper sequence. Reinstall the intake and exhaust manifold torque the bolts to the proper torque. This is a major repair and not for a novice to try.