Quote Originally Posted by GP Modder View Post
Where is that o2 sensor located? Down pipe or monifold?
Just unplug the one before the Cat in the Ubend. Fasten the 02 sensor somewhere out of the way so it doesn't get messed up. Go drive around and see if its better. Now that the gas can escape through the 02 sensor hole it will run better IF the cat is clogged. If it does run better, replace the cat. Again, I suggest buying a Down pipe with a cat so you can delete the restrictive Ubend. Wont cost you any more then just replacing the Cat.

If it still runs like ****, there is some other issue then a clogged cat.

Good luck !