I had a re-think on using the original exhaust flange as the hole through the middle would have taken forever to bore out and there wouldn't have been enough gasket face left to seal properly so I ordered the right size flanges plus a lambda boss.
First job was to weld the two bolt flange to the cats 3 bolt flange. Both flanges were 8mm thick so I was going to struggle to weld it with my MIG so I dug out the stick welder tried that for a bit and put it back on the shelf...re-think time!
Eventually I MIG welded down through the bolt holes on the 3 bolt flange onto the back of the two bolt flange and that seemed to work but one of my mates uses a TIG at work so I'll get him to go round it and seal it off just in case.
Next up was to tack the second flange onto the pipe to the rear of the cat.
I then had a rethink on the front flange to the cat as it was for a ball type joint and there wasn't enough meat around the flange to seal with the gasket as well as providing a step for gas flow.
I used a spare piece of exhaust pipe to fill in the joint.
Then another flange to be welded on, centered by the spare piece of exhaust pipe.
Then I welded another thinner pipe on the inside of this to centre and help to seal the gasket
I also tacked on captive nuts as it's a lot easier to take off or put the exhaust back on. I then drilled out the pipe for the lambda boss after cutting the boss to the right length. I'll get my mate to TIG all the way around the flange on this pipe as well, but I'll weld the boss on.
Boss fixed in place.
boss welded.Exhaust off to my mate for tigging.
Cat back from Tigging just needs checking on the car to make sure it's not distorted before I give my mate the back pipe to tig up the flange on that.