...at least I THINK its fueling...
No CEL, just a real stumble when going from off-throttle to on-throttle below 3k rpm, but most prominent in the 1.5 to 2k range, typical traffic-jam driving.
I did a little analysis with Torque app, and I see the short term fuel trim go from 0 off-idle to nearly -10 as the throttle opens. This is where the stumble seems to be. Then, the trim swings to + 5 ish and everything seems ok.
So I am suspecting the forward O2 sensor, but I don't know how to troubleshoot the sensor to try to confirm or dispel my theory. So questions are:
1 - Do you think I am looking in the right direction? If anyone has a suggestion on alternatives please let me know.
2 - Does anyone have suggestions on how to see if my O2 sensor needs replacement?