You might still try resetting the adaptives on the car and seeing if they still end up at -20. I'm not sure how long it takes the long term trims to update, but if for whatever reason they got there before you ever put the new cats on it could be that they are just going to take a while to get back to normal. I'd rather start from the middle and see which direction it goes than start on the very far end. I don't think the controller can pull any more than 20% either direction, so at the moment it can only adjust one way. I am surprised it doesn't throw a code though as I thought the LTFT being over a certain value set a code.
