Good Evening,
Back around June, I replaced my upstream O2 sensor with a Premium Bosch unit. This was due to its age and hoping to see if I could fix my rather poor fuel economy. Shortly after replacing the sensor, I would get random lean codes. I would clear the code and look at the live data. Looking at the data, I’ll have near perfect fuel trims, or ones that are in the +30% range. The code always trips at idle. There are no obvious vacuum leaks that I can tell. Does it sound like I got a bad unit from the get go?
Vehicle is a 2009 GMC Canyon, i5. 250,000 KM
Sounds like you MAY have gotten a bad one. Try replacing the Bosch with an AC Delco sensor. That is what GM uses OEM. There may be something the computer doesn't like with the Bosch sensor.
