Where were the exhaust leaks? Were they at the exhaust port/header flange connection, or somewhere in the header before the collector? That kind of leak would be the sort to cause you real trouble. If it was somewhere after that, I'd be less inclined to think it was the cause of the problem, but fixing it would make a good first step in troubleshooting since it's something that needs to be fixed anyway.
Originally Posted by 91TSI_AWD
Apparently you didnt listen to well to what I said. Oh well.
Really. What great insight did I miss in your post? Please go into greater detail explaining why reducing the size of his catback and putting a cat on the car is going to fix his lean condition and drivability issues. What theory or personal experience are you going off of to back up your statement?