P0139

[jscm]

My car is tuned flex fuel with stock catalytic still. drove the car on 91 gas for a while with no codes then recently switched back to e35. 2 minutes after leaving the gas station, gas/ethanol mixing to settle, and ECU was adjusting for the new gas, check engine light turned on with a code P0139. I deleted the code after the the gas mix settled but the code still came back. anybody has sure fix on this before I start testing stuff?can high ethanol content ruins oxygen sensor?

Sponsored

 

[Romeoridgee]

Code is for rear 02 slow response. I get that code sometimes while in high rpms. I am also catless. If codes come back repeatedly after clearing, start with replacing downstream/rear o2 sensor below cat.

 

[alxgravel]

I know on ktuner you can disable it ... You should do that.

Sponsored