Kinda like the "is he here yet thread..."

I was afraid of that. Oh well I thrive on challenges.
Do you think I can do it alone by myself with the car jacked up a foot or two on stands?

EGR flange interference?? Does the cross pipe rise up that far? Well I guess I'll find out when the headers arrive.

Just be safe(Iknow you will) and keep that car blocked up. Would be good to have a buddy up top to be your eyes while you posistion from underneeth.
By the way what are using in the way of pipe for a replacement of your cat?

Just had a reply back from Zoomer of ZZP and he says that he doesn't know how to install the rear exhaust header in our Bonne'*. :?

I would think that installing it from under the car will be tight and difficult. Has anyone with headers tried to rotate the engine by removing the front mount in order to install from the top?

If you remove the front engine mount remember to support the engine. The gm service site recomends an exotic engine support but mentions a floor jack will do. They dont mention if this work either?
I also looked up how to remove the rear (right) exhaust manifold here it is.

1. Remove the EGR inlet pipe from the exhaust manifold.
2. Remove the EGR mounting bracket bolts.
3. Remove the EGR mounting bracket.

4. Remove the heated oxygen sensor lead.

5. Remove the fuel injector sight shield mounting bracket nuts.
6. Remove the fuel injector sight shield mounting bracket.

7. Remove the right engine lift hook nut and bolt.
8. Remove the right engine lift hook.

9. Remove the exhaust manifold studs.
10. Remove the exhaust manifold.
11. Remove the exhaust manifold gasket.

Since the downpipe is 2 1/2" into the existing inlet flange of the CAT and the outlet from the CAT connects to a 2 1/2" pipe that goes into the resonator, I am going to get the local muffler shop to make up an aluminized 2 1/2" pipe to connect from the headers to the pipe just in front of the resonator. If the TOG headers has a 3" outlet, then we'll simply use a reducer and extend the 3" size as far as possible. I would like to re-use the flanged connection though.

Update on my progress today.
I have removed the rear exhaust O2 sensor, lift hook and cover brackets and I finally was able to remove those blasted plug wires.
I was able to do it all from under the car. It was fairly easy but I wouldn't want to tackle this job if I was in a hurry and needed to drive the car.
The next to remove is the downpipe.
Last is the manifold itself.....but I'm satisfied with my progress this weekend so maybe I'll wait until next weekend to do it. TOG headers won't be here for a week or two so I have plenty of time......while this soggy weather clears up. I think I will buy a new O2 sensor when I order the throttle body gasket.

Keep you posted on my progress.

Get well soon PontiacDad so you can follow along with me.

Oh, I removed the transmission dip stick tube....but it leaked out 1/4 L of my fresh trani fluid so I popped it back it until the headers arrive.

Forgot to thank you for posting those pics PontiacDad.
Depending on the new header size, it just might be easier to install from under the car.
The pic showing the spark plug routing is very helpful. It seems that the factory missed the wire loom that holds the #6 wire to the cover bracket. My wire was touching the O2 sensor and I had to tie it back to avoid an intermittent misfire. That will be corrected.

Did your headers include gaskets and fasteners?

Your welcome SilverBullet, that service site comes in handy sometimes.
The headers are not much bigger than the original manifold, maybe a bit deeper but not much.
So theres no third leg on the wire loom? I got a couple of spark plug spacers I can use to hold them. Makes me wonder where i shoved that wire last spring when I changed out the plugs?

What size is the outlet of the rear TOG header? 2 1/2 or 3"?

I ordered a replacement O2 sensor from the dealer. Wow. $180. plus tax.