Confused about P0136 code

[Terminator03]

So, I know P0136 is a bank 1, sensor 2 code, no confusion there. What I’m confused about is that I can drive my runner every day locally, including short stints on the highway for several months/indefinitely without ever tripping the code, but if I go on an extended highway trip, say an hour or so, it will throw the trifecta of dash lights (CEL, VSC/TRAC)! I have no problem clearing everything, which I do when it happens, but it does get old, and obviously I’d like to correct it so it doesn’t happen at all. I’m running Thorley shorty headers, cats, and have spacers on the sensors already. Is it likely that the sensor itself is bad? Why does it ONLY trip in that one circumstance?

 

[Zero0575]

Have you tried cleaning your MAF sensor? Sounds weird, but I recently got P0157 which is bank 2 sensor 2, and wouldn't throw that code til I got to highway speeds. I drove the dustiest (spelling?) trail of my life in CO recently so I did some guesswork and cleaned my MAF sensor, no more codes.

For what it's worth I I have a similar setup to you, doug thorley shorties with spacers.

 

[Terminator03]

Have you tried cleaning your MAF sensor? Sounds weird, but I recently got P0137 which is bank 2 sensor 2, and wouldn't throw that code til I got to highway speeds. I drove the dustiest (spelling?) trail of my life in CO recently so I did some guesswork and cleaned my MAF sensor, no more codes.

For what it's worth I I have a similar setup to you, doug thorley shorties with spacers.

That’s super interesting, and I’ve never seen that suggested before, but no, I haven’t cleaned it. Definitely worth a shot though, especially since I have CRC MAF cleaner on the shelf already. Thanks for your input!

 

[Zero0575]

That’s super interesting, and I’ve never seen that suggested before, but no, I haven’t cleaned it. Definitely worth a shot though, especially since I have CRC MAF cleaner on the shelf already. Thanks for your input!

My thinking exactly (on already having the CRC MAF cleaner). Part of my guess was that the computer sees some kind of an oxygen issue, but points to the wrong place because of the O2 spacers - purely a guess as I'm not an engineer and just a guy who likes playing in the garage.

Been driving for over a week now with no codes, so in my case it was definitely a dirty MAF sensor. Let me know if it works for you!

 

[Terminator03]

My thinking exactly (on already having the CRC MAF cleaner). Part of my guess was that the computer sees some kind of an oxygen issue, but points to the wrong place because of the O2 spacers - purely a guess as I'm not an engineer and just a guy who likes playing in the garage.

Been driving for over a week now with no codes, so in my case it was definitely a dirty MAF sensor. Let me know if it works for you!

I’ll definitely give it a shot because “why not”? It’s going to be difficult to tell if it works in my case though because I don’t often replicate the condition that trips it because even regular highway use locally doesn’t do it. It only seems to happen when I travel for around 45 minutes to an hour at highway speeds which I was doing quite a bit in the early spring working on a far away renovation project, but mostly my highway jaunts are like 15-20 minutes locally. I would try changing the sensor, but the connector is pretty messed up/melted, so there is no way to get it apart without cutting and splicing. I also didn’t want to buy an expensive sensor if it won’t fix the issue.

 

[Zero0575]

I’ll definitely give it a shot because “why not”? It’s going to be difficult to tell if it works in my case though because I don’t often replicate the condition that trips it because even regular highway use locally doesn’t do it. It only seems to happen when I travel for around 45 minutes to an hour at highway speeds which I was doing quite a bit in the early spring working on a far away renovation project, but mostly my highway jaunts are like 15-20 minutes locally. I would try changing the sensor, but the connector is pretty messed up/melted, so there is no way to get it apart without cutting and splicing. I also didn’t want to buy an expensive sensor if it won’t fix the issue.

I was wrong, the wife sent me a picture of the christmas lights that returned on the way to work today I'll be replacing the downstream O2 sensor soon to see if that fixes my issues.

 

[bear1998]

I was wrong, the wife sent me a picture of the christmas lights that returned on the way to work today I'll be replacing the downstream O2 sensor soon to see if that fixes my issues.

Check out Rockauto for pricing...they should have several to pick from with good prices. Look up there 5% code n enter on the line that says (how did you here about us). This one should be good: 150532960138402720
Pretty sure the one you need will be described as downstream ,right side....denso is basically an oem part.
I just replaced my upstream ones...i had 2 codes..leftn right side..took care of faultcodes that i had..........

 

[Zero0575]

Check out Rockauto for pricing...they should have several to pick from with good prices. Look up there 5% code n enter on the line that says (how did you here about us). This one should be good: 150532960138402720
Pretty sure the one you need will be described as downstream ,right side....denso is basically an oem part.
I just replaced my upstream ones...i had 2 codes..leftn right side..took care of faultcodes that i had..........

Oh yeah, I use Rockauto for everything! I ordered two Denso's last night, since I've heard you should replace these in pairs:

More Information for DENSO 2344261

I also ordered a bluetooth scan tool on Amazon since it was only $12 and I'll no longer need to go to an auto parts store to have codes read:

Amazon.com: obdator Mini Bluetooth OBD2 Scanner ELM327 Automotive OBD OBDII Code Reader Car Check Engine Light Diagnostic Scan Tool for Android PC: Automotive

I'll report back after I replace the O2 sensors and let you guys know if it was, indeed, my issue.

 

[Terminator03]

I was wrong, the wife sent me a picture of the christmas lights that returned on the way to work today I'll be replacing the downstream O2 sensor soon to see if that fixes my issues.

Thank you for the the update! Sucks it wasn’t “the answer”, but it was worth a shot.

 

[Terminator03]

Oh yeah, I use Rockauto for everything! I ordered two Denso's last night, since I've heard you should replace these in pairs:

More Information for DENSO 2344261

I also ordered a bluetooth scan tool on Amazon since it was only $12 and I'll no longer need to go to an auto parts store to have codes read:

Amazon.com: obdator Mini Bluetooth OBD2 Scanner ELM327 Automotive OBD OBDII Code Reader Car Check Engine Light Diagnostic Scan Tool for Android PC: Automotive

I'll report back after I replace the O2 sensors and let you guys know if it was, indeed, my issue.

Please update the thread once you’ve run them for a bit. Hopefully they’ll do the trick!

 

[Zero0575]

Please update the thread once you’ve run them for a bit. Hopefully they’ll do the trick!

Will do! It took about a week or more for the codes to return. I'll be replacing the sensors tonight and will update the thread in 2 weeks or so.

 

[Zero0575]

Please update the thread once you’ve run them for a bit. Hopefully they’ll do the trick!

Replaced downstream sensors Thursday night on both sides and my check engine light is already back on. The troubleshooting continues...

 

[Zero0575]

Just another update on this, the scan tool live data shows 0 volts on the sensor in question, Bank 2 Sensor 2 post cat O2. Does that mean there is a short somewhere? Any suggestions, anyone?

 

[Terminator03]

Just another update on this, the scan tool live data shows 0 volts on the sensor in question, Bank 2 Sensor 2 post cat O2. Does that mean there is a short somewhere? Any suggestions, anyone?

Wish I could answer this, but at least I can bump it for someone else to see that maybe knows. I can say that it does sound like maybe a bad sensor, or something with the harness itself. Did you check the voltage before changing the sensors? If not, maybe swap the old one back in at that spot. At least you’ll know if it’s the sensor, or the wiring...

 

[Ralph Blake]

Just a few questions is your gas millage changing is the preformance of engine dropping is there anything happing that makes you think your truck might soon fail?

 

[Zero0575]

Just a few questions is your gas millage changing is the preformance of engine dropping is there anything happing that makes you think your truck might soon fail?

Gas mileage I would say is unchanged or maybe 1mpg less than usual. I haven't driven it a ton since the check engine light is on just because I'm OCD and don't like staring at all those lights while driving. The idle is about 100 to 200 rpms higher when the check engine light is on. It doesn't feel like it's about to fail or anything - no hesitation or stalls or anything like that.

Wish I could answer this, but at least I can bump it for someone else to see that maybe knows. I can say that it does sound like maybe a bad sensor, or something with the harness itself. Did you check the voltage before changing the sensors? If not, maybe swap the old one back in at that spot. At least you’ll know if it’s the sensor, or the wiring...

I got the scan tool after changing the sensors, so I didn't check the voltage before changing them. I'll swap the old sensor back in and see what that shows.

 

[Zero0575]

Another update..

Instead of just using the scan tool to clear the codes, I reset the ecu by disconnecting the battery for a bit. Drove around and did some WOT runs, a screenshot of the bank 2 sensor 2 (and bank 1 sensor 2 for comparison) is attached. Looks appropriate to me - drove for about an hour today and no check engine light. I'll update again later.

 

[Ralph Blake]

Gas mileage I would say is unchanged or maybe 1mpg less than usual. I haven't driven it a ton since the check engine light is on just because I'm OCD and don't like staring at all those lights while driving. The idle is about 100 to 200 rpms higher when the check engine light is on. It doesn't feel like it's about to fail or anything - no hesitation or stalls or anything like that.



I got the scan tool after changing the sensors, so I didn't check the voltage before changing them. I'll swap the old sensor back in and see what that shows.

Reason i asked about if there was a drop in gas mileage or any problems after the check engine light came on is i had the check engine light come on then be off then come on again on my Nissan Max, that was around 10 years ago i just waited to see if gas mileage dropped or any other problem happened i drive it every day gas mileage never dropped and i just put tape over that check engine light.

 

[Zero0575]

Reason i asked about if there was a drop in gas mileage or any problems after the check engine light came on is i had the check engine light come on then be off then come on again on my Nissan Max, that was around 10 years ago i just waited to see if gas mileage dropped or any other problem happened i drive it every day gas mileage never dropped and i just put tape over that check engine light.

I appreciate that you're trying to help, but I don't subscribe to the idea of ignoring the check engine light. The engineers that made this beast are much smarter than me, so if it tells me that something is wrong then I'm going to fix it. I also actually enjoy the process of learning, diagnosing and fixing these issues.

But good news is, I believe I just needed to actually reset the ECU rather than just clicking "clear codes" on the code reader. Drove for a few hours on Sunday and Monday and the check engine light has not come back!

 

[MikeinNH67]

Seeing there's no power check the fuses under the hood. I'm pretty sure there's one that powers the front o2's and another for the rear but I forget on exactly how it's setup. There's also a relay in there that can fail, I think it is the same type as the one that fails for the A/C so you can easily try another in the fuse box.

There's a wiring diagram on this site, at least for an 03:
P0031 and P0051 Codes - Check Engine Light, VSC TRAC, VSC OFF Light - The Track Ahead