OK, this is what's going on. I have three SCT tunes on my A9L Computer. One is OPEN loop and the other two are CLOSED loop. In the closed loop tune the ECU reads the feedback from the 02 sensors. I have a wideband so I can see what's going on with my AF ratio. AF is fine in open loop tune. All of a sudden my closed loop is running very rich at cruising speed. The wideband will read 10:1. Also when I come to a stop in closed loop, I get the searching idle syndrome. As far as I know, the closed loop is for feedback from the 02 sensors and no other sensor. I checked, 02 sensors, harness to ECU and 02 ground. All check out fine. Even ran car at idle and read voltages coming off 02s to ECU and that was good. Next thing I was going to do is check the computer for any open traces. Anyone have an idea of what's going on here?
