I am starting to tune my 1998 K2500 with a 350 in it. The motor is bone stock other than a K&N intake from the previous owner and roller tipped rockers in the stock ratio. The motor has a couple thousand miles since I rebuilt it. All of the sensors were replaced and the truck runs great, other than it gets bad gas mileage. However, it does have 4.11's in the rear, so it is kind of expected.
After some tinkering in the software, I have all of the tables and graphs set up to tune(or at least I think so. Still trying to figure this stuff out). My wide band O2 sensor is also set up and displaying in the software. The wide band is installed in place of the stock driver side O2 sensor.
I went into the stock program and forced the truck into open loop in order to data log and start tuning. I also changed the power enrichment to 0 second delay. (For future wide-open throttle tuning). The truck ran like crap. It had a very hard time getting up to speed and was way different than normal. Air-fuel ratios were 14.5 at idle and 19-20 at normal driving speeds (35 mph). It drove so terrible, I turned around and went back home. I thought I probably messed up something, so I reflashed the stock tune, which is not forced open loop. Wide band O2 was still installed. Same thing happened. The truck ran terrible and had an air-fuel ratio right around 20 when driving in town. I uninstalled my wide band and put the stock narrow band O2 sensor back in. The tune was not changed at all. Runs like a millions bucks. The problem seems to be the wide band O2 sensor. The check engine light did not come on and there were no error codes when I checked.
Can anyone explain why a missing driver side O2 sensor would affect the truck when it is forced open loop? As I understand it (Correct me if I am wrong), the truck should not look at the O2 sensor's at all in open loop. It would only use the O2's in closed loop. My log and tune files are attached. Log file is in open loop. I did not do a data log with closed loop enabled. Is there some other issue I am simply over looking? Did I not force open loop in the right way? Am I just a poor boy from a poor family??? Spare me my tune from this monstrosity. Any help with this would be greatly appreciated because this baffles me to no end.