P0139 CEL code?

[builttodrive]

After installing long tubes and going to E85 I experience a P0139 Check engine code. It's an 02 sensor test and I'm told it happens on a small percentage of gt500's with long tubes. It comes on about every other tank of fuel. From what I hear it is harmless and a non important test the system performs and that the E85 is probably making it happen easier. I know it's nothing to worry about but I'm starting to get tired of clearing the code. Anyone else experience this code? What was the fix or solution?

 

[VNMOUS1]

It's because your front HEGO isn't reaching the prescribed temperature in the set amount of time.

It happens frequently with headers.

The stainless steel of headers doesn't get as hot nor does it heat up as quickly as stock manifolds. So, the system sees it as though part of your emissions system isn't ready to work. On many years it means the system won't go into closed loop fueling in the "correct" time frame.

e85 runs much cooler and exacerbates the problem.

The time frame can be extended in the calibration but that's not a guarantee that it won't come back (it will, as the O2s degrade more quickly from the ethanol)

 

[builttodrive]

It's because your front HEGO isn't reaching the prescribed temperature in the set amount of time.

It happens frequently with headers.

The stainless steel of headers doesn't get as hot nor does it heat up as quickly as stock manifolds. So, the system sees it as though part of your emissions system isn't ready to work. On many years it means the system won't go into closed loop fueling in the "correct" time frame.

e85 runs much cooler and exacerbates the problem.

The time frame can be extended in the calibration but that's not a guarantee that it won't come back (it will, as the O2s degrade more quickly from the ethanol)

BJ,

Is it worth trying to change the calibration? I know it's nothing to worry about however I have my Aeroforce gauge plugged into my obdII and since I have to un plug it every time to use my SCT to clear the code my cord on the gauge is getting sensitive and I have to wiggle it around to get it to work some times. I just don't want it to ruin my cord.

 

[VNMOUS1]

BJ,

Is it worth trying to change the calibration? I know it's nothing to worry about however I have my Aeroforce gauge plugged into my obdII and since I have to un plug it every time to use my SCT to clear the code my cord on the gauge is getting sensitive and I have to wiggle it around to get it to work some times. I just don't want it to ruin my cord.

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321.206.9369 x112