Drew1

iTrader: (1)

Codes I am getting

PO134 O2 CKT Sensor no activity bank 1 sensor 1
PO135 sensor heater sensor malfunction bank 1 sensor 1

Car gets them intermittently on E85, it has gone off on its own without have to erase the code. The pending code will not show either.

Haven't really found a pattern but it is primarily while on E85. First time it came up was when I switched from E85 to 91 and from researching it looks like it may have just confused the ECU w/ the change.

Do you think the sensor is actually bad or just the ECU figuring out the fuel? Fuel mileage does not change.

Code reader reads and cycles the volts between .800 and ~.140 for the sensor 1 on scan tool. From what I remember they were around those numbers at least.

Any other ideas? Don't really see a reason to change the sensor out since it's not changing fuel mileage...Basically just a light on the dash from time to time.

Drew1

iTrader: (1)

Supposed professional tune turned out to be a likely previous owner tune and it is now retuned. O2 sensor was weak and did go out on the dyno though. Everything all good now.

Tuning Technologies in SoCal did the tune and did an awesome job for a good price.