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-   -   OFT & Rear O2 Sensor Failure - Can I Temporarily Disable Codes? (https://www.ft86club.com/forums/showthread.php?t=120155)

nofferman 07-08-2017 10:07 PM

OFT & Rear O2 Sensor Failure - Can I Temporarily Disable Codes?
 
I'm running OFT v2.061 E85 UEL Stage 2 tune with a UEL catless header.

I was running at the track today and got a P0037 and P0141 check engine codes, putting the car in limp mode and ending my day:

P0037 - HO2S Heater Control Circuit Low Bank 1 Sensor 2
P0141 - O2 Sensor Heater Circuit Malfunction

I metered the two black wires on the rear O2 sensor (black connector), and it's reading open resistance / dead. I'm about to go pull off the undertray and see if there's any visible damage to the sensor or wires. I've had no luck finding a replacement O2 sensor on the weekend so I can keep running tomorrow.

However, It looks like I can disable those codes in RomRaider.

My question is - will the dead rear O2 sensor affect the engine performance on an OFT tune, or is it just to check cat efficiency? If I disable those codes and re-flash it for just tomorrow, will the engine run properly? I'd like to get one last day in, but not at the expense of an engine. :bonk:

Thank you!

phrosty 07-08-2017 10:16 PM

The O2 sensor does affect perf in subtle ways, consensus seems to be that it's safe to street so long as everything else is good, but I don't know if that translates to HPDE safety.

steve99 07-08-2017 11:52 PM

Quote:

Originally Posted by nofferman (Post 2942752)
I'm running OFT v2.061 E85 UEL Stage 2 tune with a UEL catless header.

I was running at the track today and got a P0037 and P0141 check engine codes, putting the car in limp mode and ending my day:

P0037 - HO2S Heater Control Circuit Low Bank 1 Sensor 2
P0141 - O2 Sensor Heater Circuit Malfunction

I metered the two black wires on the rear O2 sensor (black connector), and it's reading open resistance / dead. I'm about to go pull off the undertray and see if there's any visible damage to the sensor or wires. I've had no luck finding a replacement O2 sensor on the weekend so I can keep running tomorrow.

However, It looks like I can disable those codes in RomRaider.

My question is - will the dead rear O2 sensor affect the engine performance on an OFT tune, or is it just to check cat efficiency? If I disable those codes and re-flash it for just tomorrow, will the engine run properly? I'd like to get one last day in, but not at the expense of an engine. :bonk:

Thank you!

as well as disabling the cel codes you will need to set the AF#3 (rear 02 sensor) learning limits to zero theirs three tables see here, alse fueling will go weird when your cruising on highway.


http://www.ft86club.com/forums/showp...78&postcount=4

aagun 07-09-2017 01:19 AM

Also ilde AFR target to 13.8 .. for 30s then back to Normal

nofferman 07-09-2017 02:13 AM

Thank you for all of your quick replies. I think tomorrow is off. After getting under the car, there's a couple other things besides the O2 sensor that are questionable. Looking like it's smarter to get everything fixed up properly, add a couple other mods I've been wanting, and go back another time.

Thanks again!

steve99 07-09-2017 06:07 AM

If wiring melted otr sgorted, you will likely have blown fuse called EFI HTR.

nofferman 07-09-2017 12:37 PM

Just checked it, EFI HTR fuse #29 is good.

It's possible that the wire was broken from contact with a brake duct, as it runs close to the header there and sits very snug against both O2 sensors. It's been OK for 2-3 years but it's time to find a more reliable solution for that too.


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