I just bought an O2 sensor for my 2001 Blazer with 111,000 miles (4.3 L engine) after getting it serviced. I have no clue where to put it. The servicer said it was Bank 1 Sensor 2, and absolutely NO ONE can give me a certain answer as to where that is. I was hoping maybe there was some sort of diagram to show where the O2 sensor is, because someone told me it was after the catalytic converter on the driver's side, but I have only found one O2 sensor after the converter, and it is on the passenger side. The service code was " P0141 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)". I really want to get this fixed, because Service Engine Soon lights really piss me off!
If im not mistaken witch I could be your vehicle should have 3 sensors 1 on left side before cat. 1 on the right side before cat and one after cat there for the 1 on the left would be b2s1, the one the right before cat would be b1s1, and the one after cat would be b1s2. Hope this helps.
January, 31, 2007 AT 6:43 PM
Ok i'm gonna take a stab at this, i've worked on these motors plenty of times, but it's been a while. I'm used to reading o2 sensor data on the scan tool to inform me of which is bank (1) or bank (2). With a 4.3 you should have (1) o2 sensor on the left side and (3) on the right. I believe the sensor you're looking for is the one before the cat convertor. The other (2) will be sensor (1) on the left and sensor (1) on the right. I hope i'm making sense to you, anyway let me know and good luck : D
February, 1, 2007 AT 8:06 AM
Sensor 2 is behind the cat, strictly measures the efficiency of the converter. If you vehicle only has one behind the cat thaen that is it, sometimes they call for bk1 or bk2 behind the cat but there is only one sensor. Otherwise the drivers side of the engine is bk1