Its a Bosch O2 sensor.

 

I have not personally had problems with Bosch O2 sensors (but that is on mid-90's 3100's). I will tell you, I have read a LOT of people in late 90's to current GM cars NOT happy with Bosch upstream O2 sensors. Also, a guy I call my GM Guru will tell you when he works at the dealership, he's been through them all and says it's not worth dropping in anything other then AC Delco or Delphi O2's (others are two hit or miss).

I honestly would switch your upstream O2 for a AC Delco. Keep in mind, the factory tunes these cars to the specs of an AC Delco O2. A BOSCH may work, but it's specs and data readings may differ from a AC Delco one in such as way that new works great but as it wears a little is out of what GM tuned the car for.

 

k. Ill switch it out, If all else fails.

 

I check the volts on the MAF connector.And the voltage coming from the connector was 11.60-11.62, not 12 like the book said it should be. So Im going to check the wiring and ground.

 

FYI - If you are not sure if the sensors are factory original, then sometimes the readings won't match up with the book (aftermarket ones may be acceptable, but not on the money).

ALSO - I was thinking about this last night. Check for vacuum leaks. Those can also cause this problem. See a line dry rotting, time to switch it out.

 

k. so the voltage coming from the ECU to the sensor even if low a little bit, shouldnt matter.


I already checked the vacuum lines and found no leaks or rotting ones.