O2 sensor codes

[Paddy]

First post here. I just bought a 2013 Tahoe SSV. Real clean and minimal holes. But my question is not related to the SSV type, so I post here.

It's throwing codes for the O2 sensors, P015B and P015D. Delayed responce-Lean to Rich, Banks 1 and 2 Senors 1

How to tell if it has bad catalytic converters or just bad sensors?

 

[swathdiver]

Check again, don't think there should be any letters, looking for the letter P followed by four numbers.

 

[Paddy]

Check again, don't think there should be any letters, looking for the letter P followed by four numbers.

I googled it as a code;

When an OBD-II equipped vehicle has a stored P015B code, it means that the powertrain control module (PCM) has detected a delayed response time from the upstream (first one after the exhaust leaves the engine, in front of catalytic converter) oxygen (O2) sensor or circuit for engine bank one.
P015B O2 Sensor Delayed Response - Lean to Rich ... - OBD Codes
https://www.obd-codes.com/p015b

 

[swathdiver]

Well, I was trying to help out and looking in my service manual and there are no lettered codes like that for the GMT900s. What are you using to pull codes?

 

[Paddy]

Well, I was trying to help out and looking in my service manual and there are no lettered codes like that for the GMT900s. What are you using to pull codes?

A Bosch reader.

But the check engine light is now gone/cleared. But there is more to the story I didn't think was relevant so I didn't mention it. When I bought the Tahoe 3 weeks ago, it had the P0521, Pressure sensor and the O2 sensors codes. The dealer had said he replaced the filter and oil sensor but codes persisted.

Then yesterday, I checked again and only the O2 codes were there. That was when I posted. Later in the day I drove for 30-40 mins and noticed the check engine light was gone.

They could reappear

And maybe because it was a cop car it idled alot just needed driving. Or maybe, when the P0521 code is showing, it runs in a less efficient way making the O2 sensor kick in. As in codes making other codes activate?

In any case, fingers a crossed.

 

[swathdiver]

When things are changed and codes reset they should be driven at least a couple of minutes above 25 mph to reset the lights/computers. You should be good to go.

If you those were codes P0151 or P0152, then the throttle plate might be dirty.

 

[Paddy]

When things are changed and codes reset they should be driven at least a couple of minutes above 25 mph to reset the lights/computers. You should be good to go.

If you those were codes P0151 or P0152, then the throttle plate might be dirty.

The O2 codes are back after 50 mi with no check engine light.
At least the P0521 code has stayed off. I might need to replace the O2 sensors and hope that does it

 

[Cattivo]

I get similar codes every once in a while that really annoy me after changing all 4 02 sensors numerous times...I'm pretty sure my trucks cats are bad, maybe yours are bad as well. Hopefully when I swap out the engine and exhaust this will all be a bad memory

 

[CobraKing]

@***** I have P015D on my 2014 PPV and I believe that it's the upper bank, passenger 02 sensor (right before the CAT). P015B is related to the upper bank, driver 02 sensor (but please do correct me if I'm wrong). In any case you should replace the 02 sensors in pairs so both uppers or both lowers (after the CAT) at the same time.

For those of you that have replaced the 02 sensors, how difficult was it to access the upper, passenger 02 sensor with the car on ramps/stands? I looked at it quickly last night and it seemed quite hard to stick a wrench or socket in there when sliding under the car from the front. Are there any tips or strategies? Thanks.

 

[Paddy]

@***** I have P015D on my 2014 PPV and I believe that it's the upper bank, passenger 02 sensor (right before the CAT). P015B is related to the upper bank, driver 02 sensor (but please do correct me if I'm wrong). In any case you should replace the 02 sensors in pairs so both uppers or both lowers (after the CAT) at the same time.

For those of you that have replaced the 02 sensors, how difficult was it to access the upper, passenger 02 sensor with the car on ramps/stands? I looked at it quickly last night and it seemed quite hard to stick a wrench or socket in there when sliding under the car from the front. Are there any tips or strategies? Thanks.

CobraKing,

I have a Bosch OBD 1100 scan tool. While driving my wife was checking the live data. My understanding the "pre-Catylic sensor" should fluctuate from .02 to .8-9. Both sides did. The after should hold steady at about .5, both were in the the .45 range.

I'm new to scan tools and certainly understanding how/when to read live data. I noticed the fuel pressure at 43 psi but I have a flex fuel and not sure what the level should be. Regular engines should be 55 65 psi I recall.

I mention fuel pressure because one of the issues that can make O2 sensors throw a code is low fuel pressure. With this Tahoe being an SSV with 145k miles, and plently of idle time, the pump may have and equivalent of a 170k miles. Alot of fuel pump run time.

Other issues that I read on line that can cause O2 codes are;
Harness, short or loose conection
injectors
intake leak
Vacuum leak
Exhaust leak
Catylitic Converters