Howdy all,

It seems my truck is not contempt with staying fixed, regardless of the money or TLC I give her. I had a plethora of O2 related codes in 2023 which have since, or so I thought, been fixed. I just got back from being abroad for roughly ten months (I was back in the states in May and drove the truck ~150 miles with no issues) but noticed a bit of a rough idle yesterday. Low and behold I get the truck back from the alignment shop this morning and voila, P0132 rears its ugly head once more. Prior to leaving the country I had put about 1000 miles on the truck with no issues. Below is all the relevant information that I have:

1. O2 sensors were all brand new and purchased directly from NTK
   1. As a note, they apparently only sell one sensor, not the upstream and downstream so the four purchased were identical to one another. Not sure if this might be the issue or not but everything ran well for hundreds of miles with no issues.
2. Catalytic converter was purchased new in 2021 and has only ~2000 miles on it
3. I do not have stock exhaust, there is a glasspack straight off the catalytic converter to a downpipe.
   1. Unsure if the lack of back pressure could have something to do with this? But P0132 is for bank 1 sensor 1 so back pressure shouldn't play into it if I'm not mistaken?
4. The only thing under the hood that looks slightly off is the PCV valve and the associated vacuum line; it appears as if oil is leaking out of it, and the line looks to be "sweating" for the lack of a better term?
   1. As a note I have aftermarket valve covers so perhaps the seal around the PCV valve isn't proper? I just checked it and the PCV appears to be functional although there were a few specs of oil in the line immediately after the PCV valve and in the metal port leading into the intake manifold, although not much, barely enough to get picked up on a q-tip. I can upload pictures if needed.

I previously verified that everything was functional, and in fact my previous codes were due to a mix of non OE sensors and parts which have since been corrected and verified as the vehicle pass CA smog in 2023. I'm scratching my head here as what could be the issue. If anyone has any suggestions that would be great but I plan to verify the following... again...

1. Swap Bank 1 Sensor 1 to Bank 2 Sensor 1 and see if the code persists on bank 1 or transfers to bank 2, more than likely meaning a failed sensor
2. Continuity of voltage/ground between harness and PCM
3. Voltage signal from PCM to connection at harness
4. Check for vacuum leaks with starter fluid
   1. All vacuum lines on the vehicle were replaced with performance grade silicone ones in 2023 so I doubt this is the issue, unless something is up with the PCV

If there is anything I've missed or any suggestions I'm all ears... Thanks!

 

Need to plug in with a scanner, and see just what voltages the sensor is giving out. Is it within the 'normal' range? (0-1 volt sensor output)

 

Unfortunately my scanner grew legs and ran away since I can't find it; ordered another that'll be here in 14 hours so I'll check and report back. In the meantime would you suggest I verify everything else or just wait until I'm able to check what voltage the sensor is sending to the PCM?

 

Wait and see what the scanner is reporting. The *might*...... point in the right direction. Or not......

Have you replaced the PCM by any chance?

 

I have not replaced the PCM. It along with the driveshaft, leaf springs, cruise control bellow, vacuum vapor cannister, and brake booster will be quite literally the only things on the truck that have not been replaced. I've spent a LOT of money and time on this thing lol

One of the previous owners might've though as there is white sharpie writing on it stating the year and engine size, so either a junkyard PCM or a flashed PCM, which gives me some concern.

 

Junkyard PCM would be my guess. And yeah, that IS suspicious..... Though what would be really enlightening is WHY it was replaced in the first place.... O2 sensor codes perhaps??

 

Just for reference this what my PCM looks like:

 

Clear the code then swap sensors, If you get a code for the opposite side then you know it's the sensor.

Also may be a non Cali PCM. Disconnect bank 2 sensor 1 and see if you get any codes. If not it's not a Cali pcm.

 

What's the part number on the PCM? (I can't really read it...)

 

Using the enlargement feature on the photo, it appears to be part number 5640410AB with a software update...

Definitely appears to be a junkyard PCM..