P0174 and Pending P014e, and P015c. Need some help decyphering o2 tests

To start off, I am working on my 2014 DC 4x4 sport with 235k miles. On my last trip, I got a check engine light and TCS light one. Orignally, I checked the code and it came up as a p2197. I cleared to code and drove home and light came back on. When I got home, it showed as a p0174 and pending p014e and p015c. I checked voltage on the O2 sensors as shown below.

O2 B1S1- moving voltage between 3.2-3.35V
O2 B1S2- Started at .055v and moved to .195V over about 90secs time
O2 B2S1- moving voltage between 3.28-3.4V
O2 B2S2- No voltage at all

MAF was moving between 4.6-7V as well.

Guessing my culprit is Bank 2 Sensor 2 stuck and causing the somewhat stagnent voltage on B1S2 but I just haven't done this enough to know for sure. Thoughts from the experts? Also If I have research correctly, B2S2 is the bank 2 downstream sensor correct?

 

So you need to check the freeze frame data the next time it triggers. Don't blow the code out. The only way to find out what is wrong is using the data.

What is the lamda, the voltage of the sensors during failure, what is the fuel trim etc.

It's more likely B2 S1 the upstream sensor on the drivers side. But if you're not getting any voltage from b2s2 even after warm up it's definitely more of an issue.

 

I haven't cleared the codes again and can go get that data. I didn't think about the warmup effecting voltage as I tested the voltage of the sensors within just a minutes of starting my truck for the day.

 

02 sensors typically need a drive to wake up. I rev the piss out of trucks for a few minutes until I get consistent readings.

 

The PCM delays turning on the heaters to wake the downstream sensors for a few min after startup but the upstreams should come online in under a minute.
If you are on original sensors at 235k it may be time to replace them, sometimes they start getting lazy/skewed at higher miles.
Also check them for oil contamination and address any leaks that are getting on the outside of the sensor(s) or harness as I have seen that alot of times when the outside of an O2 sensor gets soaked in oil it starts giving false readings.

Here's a couple examples of what your AFR & O2 Sensor signals should look like.

Cold Start



Driving

 

Thanks for that info. I record and save the freeze frame data on the reader last night, after warming the truck up but I didn't see any way to view graphs. I'll have to go look and see if charts like this are availble on my scan tool.

 

So I am not finding a way on my tool to display charts. I recorded the freeze frame data but there doesn't seem to be a way to visually assess it. Is there readings I can share from it that will help us narrow things down?

 

At that milage I'd replace all 4 02 sensors. Then go from there. Inspect each one for oil/water when you pull it

 

sounds good. I'll start there

 

On the graph data you want to see the upstream sensors switching high low and the post cat o2 should look fairly flat.

 

I cannot get it to display a chart. It says its recording the data but I cannot find a way to look at it on a chart.

 

Just ordered the mexico spec sensors since I have a mexico vin truck so i'll report back when they come in and hopefully get this issue fixed

 

What scan tool do you have?
Most support live data and alot of them support graphing.

 

Fox well

$70 nt301 OBD2 scanner live data professional mechanic OBDII diagnostic code reader tool for check engine light

nt301 from Amazon

 

Well I got all 4 A/F & O2 sensors changed with new NTK Sensors and drove for 600 highway miles and all looked good. Went for a drive yesterday locally and CEL came back on showing P2241 Low Heater Circuit voltage on B2S1. I didn't read until after installation that I should have gone with Denso only sensors but would this cause a CEL? I have a new scan tool if running additional tests is the next step. Just feeling a bit lost and defeated at this point so any help is much appreciated.

 

check engine and TSC lights voluntarily turned off now