Removing the whole exhaust

[carl]

Yes, I have reached that point in my life where I'm forgetting how I used to do stuff, albeit I was usually doing things the hard way.

Since I have a header and 79 muffler for Project X, I will be removing the entire stock exhaust from this injected X. The rear bumper, rear grill and lower valence have been removed. What is the easiest way to remove the exhaust? Assume all threaded fasteners will need heat to remove. Oh yea, I mean from below the manifold.

 

[Dan Sarandrea (Phila)]

I was thinking that you should first disconnect/snip the O2 sensor wire, heat up if necessary and remove the O2 sensor, then loosen the three manifold to downpipe nuts, then instead of wrestling with the springs, just unbolt the spring hangers from their captive nuts in the runk pockets. Then undo the center bracket to the trans/crossmember.

With the downpipe loose on the mani, the O2 out of the way, and the hangers loose or removed, it should become evident whether the combination of the muffler and cat can drop out as one assembly, or if further separation will be needed.

Not sure if removing the O2 sensor is strictly needed for clearance, just recognizing that it might be easier to muscle it off while the downpipe and the rest of the exhaust is still secured to the car.

 

[carl]

That was my plan, I did not consider removing the O2 sensor but you make a good case for removing it. I just don't recall if the whole assembly would drop out with the down pipe passing through the firewall. I didn't want to get it hung up halfway out and then have to start separating parts. The fasteners appear well beyond spritzing with penetrating oil so I'll be going straight to the torch to head up fasteners.

 

[MikeHynes]

Carl,
I recently dropped the exhaust on a '79. I had to remove the pipe that is attached to the manifold and goes through the body to the cat. The cat and muffler stayed together.

 

[carl]

Just finished this project. The cat/muffler combo dropped right out after unbolting the cat from the down pipe. Fortunately, of all the rusted, fused, daunting joints in the exhaust, the joint of the cat to the downpipe had been rebolted at some point with four stainless steel bolt/nuts and they easily came apart. Feeling lucky, I thought maybe the manifold and headpipe might come out as a unit but alas that was not the case, just not enough wiggle room for the downpipe to pass through the fire wall still attached to the manifold. I got pissed and cut the down pipe in two and then the combo pulled up and out! Now I can clean things up and install the header/79 muffler.