I recently found that I had a broken spring. I had the head repaired and I replaced the lifters and put everything back together. I'm concerned because when I was on 7 cylinders everything in the tune looked ok except the o2 readings in bank 1 were low. Now at idle, the lt readings are in the read also they flash red at 16 at certain points during the pulls. like 5800. I'm not sure about this. I only have a scanning version of hp tuners. i though that after fixing the head, that all would be well. because the car was tuned with all 8 cylinders.