P0135 O2 Sensor Heater Circuit Malifunction (B1S1)
 

Last month sometime I had a P0147 (B1S3) code come up and I posted it in a thread (search for P0147).

It was suggested that I clear the code and see what happens. I did, it hasn't come back on.

Today as I left work, my 'Check Engine' light came on and I got a P0135 (B1S1) when I checked it at home.

In the previous thread, it was mentioned that B1S3 shouldn't affect the mileage. Will B1S1 affect it since it is before the Cat?

Should I take the same steps as before, reset and only replace if it comes back on?

Also, if I need to replace the B1S1, is it pretty much the same as the B1S3?

Thanks,

Allan

RE: P0135 O2 Sensor Heater Circuit Malifunction (B1S1)
 

B1S1 is a different sensor than B1S3. I believe the front sensors are an AFS105 (I can check that later against the packages still on my shop bench).

Typically a heater malfunction is a sensor fault and will come back after each complete drive cycle after clearing the codes. GM Drive Cycle

B1S1 is the drivers side sensor and B2S1 is the passenger side. B1S1 always coincides with the #1 cylinder on the engine.

Good luck and let us know.

RE: P0135 O2 Sensor Heater Circuit Malifunction (B1S1)
 

Thanks for the info. I think that I may replace these sensors.

I was looking through my ALLDATA info and there are 3 heated O2 sensors: B1S1, B1S3, B2S1. ALLDATA indicates that the part number is 25312200 which translates to ACDelco AFS105. This would indicate that all three sensors are the same. Can you (or anyone else) confirm this?

I did notice on ACDelco's site that there are 2 required sensors labeled 'Front of Converter' and 1 required sensor labeled 'Post Converter' yet both are indexed as AFS105. I just want to be sure that all these are the same.

If it helps, I have :1999 CHEVROLET BLAZER V6 4.3L 262cid GAS FI N Engine VIN = W.

Thank you.