Quote Originally Posted by rspears View Post
If that's the O2 sensor for the EFI feedback that leak had to be playing hell with the EFI, trying to compensate for excess O2 in the exhaust when it was really coming in from the leak. Not a good deal, there.
Yes it is and I'm betting yes it was. It has a really bad surge at idle and backfires during part throttle acceration. That usually points towards running lean, but if it saw excessive O2, you would think it would be loading up. I'm curious to see how it runs when I'm done.