P0141 - Replaced sensor, SES light still on

jBlaze3000 · June 12, 2012

Replaced the drivers side, downstream O2 sensor today after getting the P0141 error code on my Suburban (5.3). Disconnected the battery for a few minutes, started the truck, and the SES light is still on. I felt the new sensor with the truck running and it was barely warm. These should heat up upon start up, shouldn't they?

One thing about the sensor - it's an AC Delco that I got on clearance at Rock Auto. Physically it looked like the right replacement (same threads, same hex size) but the electrical connector had an extra tab on it. The new one looked like the picture below, with those 2 aligning tabs in the middle, whereas my old sensor only had 1. Because of the extra tab it did not fit. I ended up popping out the electrical pins and swapping the connectors.

Anyone ever experience this with their new O2 sensor? When I get home tonight I'm going to check voltages but is there a fuse for these?

00Silverado4x4 · June 12, 2012

No insult but was the sensor meant for your truck? The thread and hex size could be the same but if the sensor composition, dimensions, design is wrong it may not work correctly. I understand saving a couple of bucks but if the purchased part was meant for another vehicle it'll be hard to predict what it will/won't do when installed on your truck.

txab · June 12, 2012

You can also have a bad cat. It happens. No sensor will fix that. Make sure the code is cleared when you do try to clear them. Make sure you have the CORRECT O2 sensor for your vehicle. What year burb? Part # you purchased.?

jBlaze3000 · June 12, 2012

No insult but was the sensor meant for your truck? The thread and hex size could be the same but if the sensor composition, dimensions, design is wrong it may not work correctly. I understand saving a couple of bucks but if the purchased part was meant for another vehicle it'll be hard to predict what it will/won't do when installed on your truck.

None taken. According to Rock Auto it was the right one for my vehicle. It was a clearance item and it said there was 1 remaining so it's not even posted on the website anymore to look at. At $17 bucks I figured may as well swap out the connector and see if it works. I should know more after I take some voltage readings tonight. At least I know what the connector looks like now so if I'm getting voltage to the sensor I'll just buy the sensor with the correct connector for $20 (and still save about $10 over Oreilly's):

jBlaze3000 · June 12, 2012

You can also have a bad cat. It happens. No sensor will fix that. Make sure the code is cleared when you do try to clear them. Make sure you have the CORRECT O2 sensor for your vehicle. What year burb? Part # you purchased.?

2000 Suburban LT. It is actually a BWD/Niehoff # OS2013. Had it confused with some other AC Delco parts I bought at the same time.

**EDIT** Shouldn't these sensors heat up when the vehicle is started? Because mine is not, which leads me to believe that the replacement sensor is incorrect/defective or else it's not getting voltage (as opposed to a bad cat).

jBlaze3000 · June 13, 2012

So I went home last night and got out the volt meter. Have 12 vdc going to the O2 sensor, ground wire is grounded and resistance across the heating element = 15 ohms (quick internet search told me this was good). Based on all of this the thing should work, right?

I hooked up the electrical connector, left the sensor out of the exhaust pipe, and started the truck. O2 sensor started getting hot so it appears the heater element is working (thought these were supposed to get almost red hot so I didn't think it was working before). Also, there was strong exhaust flow out of the sensor port which tells me I don't have a plugged cat.

So I'm left with the following possibilities:

1. Sensor is working but code didn't clear - is there maybe something else that needs to be done (other than unhooking the battery for a few minutes) to clear the SES light?

2. Faulty signal wire - this would be kind of tough to troubleshoot because I believe these sensors only put out about a 1 volt signal.

3. Wrong O2 sensor - Like 06Sierra said, maybe this is the wrong sensor. The part number on the sensor was Denso # 234-4650 which is not what I ordered but is listed as fitting my vehicle on Rock Auto. As I mentioned earlier, the connector that came with it didn't fit.

4. Cat issue - like I said it's definitely not plugged, could there be something else wrong with it that's making the downstream O2 sensor throw a fault?

00Silverado4x4 · June 13, 2012

I'm not sure how long to disconnect the battery to reset the system so sanity sake take it to a local auto parts store and just have them do a reset. Then if it pops back up you can see if you fixed your problem or hopefully not have a new problem (code wise that is).

jBlaze3000 · June 14, 2012

Well the problem appears to be fixed. I went to the auto parts store yesterday and used their code reader to clear the SES light and it hasn't come back. For some reason disconnecting the battery must not have been enough to clear it.

I went into NAPA and asked for their code reader and they looked at me like I had mushrooms growing out of my ears so I had go down the street to O'Reillys to get one. Lol.

00Silverado4x4 · June 14, 2012

Yeah the local NAPA's here don't do code reading/resetting either. Well I've got my fingers crossed that your problem is fixed.

gmtech4 · June 15, 2012

its good to not try a battery BS code clear ...

always always always go get it cleared with a scanner,,,

to everyone !!!

jBlaze3000 · June 15, 2012

Well the SES light came back on today (P0141) but I think I know why now. There are different O2 sensors for Suburbans made in Canada vs Suburbans made in the US and Mexico. I bought the Canadian style sensor which was not the right one for my Burb. As far as I've been able to find, the only real difference is in how these sensors are grounded. The US/Mexico style is case grounded (the sensor is grounded to itself) and the Canadian style is an isolated ground (gets its ground from the PCM).

Still not sure why that would cause the error but I'm going to swap it out with the right part and will post the results.

gmtech4 · June 16, 2012

you are getting bad info ,this is canadian built schematic ,we need an american tech to look up the same info at GMS service info site for comparison

i cant see it getting a ground thru the exh system,,they have to be external ,in the canuck pic ,its G104

Heated O2 Sensors— (Canada Built Vehicles Only)

jBlaze3000 · June 16, 2012

I believe this is the schematic for the US/Mexico built trucks (like mine). Here's the only link I could find that tried to explain the difference between the two, and after looking at the two schematics I still don't get it.

http://www.lt1swap.c..._o2_sensors.htm

jBlaze3000 · June 16, 2012

...looks like the hot and ground wires (C&D) are reversed in the two styles, still don't see why that would make a difference though. I have the new (right) sensor on order so we'll see if that fixes the problem.

jBlaze3000 · June 20, 2012

New sensor has been installed since Monday with no SES light.

I may go back and check the Ohm readings on the new sensor just to compare them to the Canadian sensor. Anyways, moral of the story is that there are different O2 sensors for this vehicle depending on where it was built.

An O2 sensor for a Candian built truck will not work in a US/Mexico built truck.