Nut/Bolt on the left is impossible to get to. The nut is under the bottom flange. Nut for front bolt is already off.

My Dewalt DCF899. Great tool
I'm trying to replace failed cats. Two of four flange nuts came out pretty easy with about an hour soaking in PB and then quickly torqued them out with my Dewalt cordless impact wrench (great tool by the way DCF899 - 3 torque settings with about 700 lbs torque - pic attached). The other two nuts were not easy to get to with the dewalt. I had to muscle one out and the nut and bolt came completely out. That's not so bad I planned on replacing the bolts anyway. But the last nut/bolt is a challenge. Given its location I've got no way to grab the nut with a socket/wrench. I have included two pictures showing the flange and the nut & bolt which is on the passenger side, rear end facing bolt. Any suggestions on how to get it out? I was thinking of cutting off the bolt, heat it, and then grabbing what's left with some vice grips but I think all I'll do there is strip the bolt. Besides that even with the cat out it will still be very tough to get a grip on it to get it out. Does anyone know any tricks I can try to get it out? By the way I can't get at the bolt with my air ratchet either.

 

When I did ours I used a ten inch extension, a six inch wobble extension and a swivel socket to get to the nut.

 

Okay thanks for the info. I will give it a shot this weekend.