I've been able to get the 2 downstream bolts out, but have been struggling with the 3 upstream nuts. My 1/2" impact wrench sockets are bumping up against the cat so I can't get them over the nuts, so I tried a 1/2" to 3/8" conversion with my 10" extension and a deep 14mm socket. Any suggestions for getting at these bolts without using a 10" extension? Anything I'm missing?

Thanks in advanced, I'm going to go spray them again.

 

What do you use to spray them? I find PB Blaster to work best. Much stronger than WD-40 and other lubricants.

 

I've been using PB Blaster and Sea Foam's Deep Creep.

 

I did this project a few weeks ago, easiest way is to use heat.

 

Punky, are you saying to attempt removal while the cats are warm from running, or are you suggesting using a torch to warm the nuts?

 

Use a torch and get them nuts red hot and then try to break them loose.

 

Either heat them up with a torch or cut them off with a cutting wheel only takes about 10 minutes max if that for 2 bolts. If there welded onto the pipe then just heat them up and spray them with some PB Blaster.