I have an intermittent issue that I cannot pin down as to the cause. It happens while crusing and usually above 55 mph and it usually takes a while for it to start happening. When it occurs I see the wideband go rich. If I let off the throttle it will usually go back to normal. The issue appears to get worse in hot weather and higher speeds. I have verified the wiring for HEP, MAP, TPS, CLT back to ECU as well as grounds and vref's. When it occurs the fuel pressure stays up and I get no code set. What traces/gauges do you recommend using to start with? Any info appreciated. Thanks.