I just completely rebuilt the intake this past summer because of the same problem, but the CEL came back soon after that. I just got a new y-pipe and want to keep the new convertor from burning up so I am trying to figure out the problem. I used a torque wrench on all the gasketed surfaces so I'm not sure if that is it or not. I'm stumped. Any suggestions on what to try first. Thanks.

'97 Contour gl V6 ATX sho shop CAI, DMD, rebuilt intake, metal waterpump Ford 9mm Racing Wires TH fix Wish I had a third pedal