I have been running a tune from a well known tuner. We have been trying to work out this problem. After a few months I noticed that my A/F ratio was starting to richen up at WOT and half throttle(11.8 to 12.0). No other changes have been made. I had to take some fuel out to get back to 12.6 to 13.0@ WOT. Just recently even while 6% out it still is only 12.5 to 1. I have also cleared the KAM and reloaded the tune. I am using an Lm-1 for A/F measurements. I just bought a new Bosch sensor also and I know that the controller is calibrated corrtectly(I recalibrated for the new sensor). Reads 20.9% oxygen when the car is left sitting for awhile and on cruise the A/F is 14.4-14.9 to 1. Both the Brenspeed and the Bamachips tune are on the rich side. So I think that the problem lies with my car. I was thinking of getting a tune from VMP or Tillman speed, to compare the base tunes. Just wondering if anyone here has had a problem similar to this. Any suggestions would be great.