oxygen sensor bank 1 sensor 2
 

Hi guys, first post for me, here goes....So I have read all of the posts related to this, and everyone is really helpful on this site. But what I NEED actually is either a PART # for this sensor, so that I buy the correct one, or, do any of you know the wire length (seems to be important) as there are several similar sensors, but with different wire lengths. The code my SES light brings up is PO141, bank one, sensor two, heater not functioning. Any response would be greatly appreciated! Thanks Bill

If it is asking you for differences, year, model, engine and possibly vin code (W or. X) might help. ;)

Well, as I said, this is my first post, and I MUST apologize! I feel rather stupid that I didn't include more info, so here goes- My vehicle is a 1996 Chevy Blazer, LT trim, and of course the 4.3 liter gas engine, engine code "W". 90,000 miles, pretty much rust free, been stored in a garage for several years, I'm just trying to bring it back to life. She runs good, doing little repairs here and there. Of course ABS light is on (but that doesn't really concern me). The "service engine soon" light came on when I first bought it, after driving about 15 miles. After I drove it home, I plugged in the analyzer and it indicated "bank 1 sensor 2 heater inoperative" and then I reset it, the light came back on again after about 30 miles of driving. I reset it again, and came on after 85 miles of driving. So I'd like to replace it, and would like to know if there is a part # for this sensor, or known wire length for this sensor. It is the one after (downstream) of the cat converter. Thanks for any help! Bill.

That code tells you that the PCM does not like how long it takes for the O2 sensor to come up to operational status. The assumption is that the heater circuit is not working correctly. That can be the heating element in the sensor or the the circuit wiring, voltage, ground or the PCM control. Before replacing the sensor you should test the circuit.

George

Delphi ES20317
GM Genuine AFS105

Are you certain this is the post-cat sensor. I'm looking at a '97 service manual and it shows four sensors. I'm showing B1S2 as right in front of cat. I think '96 & '97 had same set up. Easy enough to check heater circuits on both if needed. Do you have a test lamp or DVOM?

I do not have any test equipment, other than a multimeter. No manual either, but I WILL get one. I've perused dozens of threads from different sources, and some say 3 sensors, some say four, very confusing. But the majority seem to point to 3 sensors. I need to add that the previous "owner" replaced the cat ( he said it was clogged ) and replaced the sensor on the cat (upstream?), which leaves the sensor after the cat B1S2, as the culprit, I guess. I believe the scanning tool indicates "bank one sensor two heater malfunction". Thanks for all your help, I guess I need to purchase the manual, but any more input from you guys would be greatly appreciated! Bill

Oh, by the way, one post I am referring to is "Oxygen sensors, how many and where?" posted by "Supercity". Check it out, what do you think?

A multi-meter is fine, what I meant by DVOM. Basically you just need to confirm you have voltage coming thru the heater circuit. The heater circuit on your truck should be the pink and black wires. You're going to want to disconnect the sensor at the plug, turn the key to the run position and measure across the terminals on the harness side that correspond with the pink and black wires. You should see voltage that will confirm your O2 heater circuit is working.

Note before doing the test, clear the trouble code. This will insure that the PCM has not shut down that circuit because of the problem. Also, you may want to have someone help so they can turn the key to RUN (not START) while you hold the meter leads on the terminal ends. Not sure how quick (or if) the PCM will shut down the circuit due to detecting an open.

I will post a pic of the terminal ends as soon as I get a chance. You can also go to Alldata.com and buy an online subscription for your truck that has the service manual and wiring diagrams, etc. Doesn't cost much at all.

Below is a pic of the connector in my '97 manual. I believe it is the same for a '96. In this photo you want to connect your meter leads across what would be 'C' and 'D' (black and pink). Do not shove your meter leads into the terminal ends or you could damage them. Just touch the metal ends.

https://cimg1.ibsrv.net/gimg/blazerf...c46f468ae7.jpg

It's best to load the circuit at or near the rated current while testing. A heavily corroded wire or connector will still show 12v but fail when the load attempts to energize.

George