i have a welded cat. conv. on my car thats rotting out . im trying to do the job myself so i want to convert it back to some kind of bolt on version since i dont have a welder. so just wondering if you can buy adapters to change it back to a bolt on version or not? also how much would a good estimate be on welding it on if i have to take it to someone? thanks

You would have to weld the flanges on. Then it would be a bot on setup.

At least get a high flow cat while you're at it. Weld shop will put on the flanges, and you'll need them to put on an O2 sensor bung (be specific where--factory position would be most desireable).