O2 sensor question, advice needed----->

[TokenBlackGuy]

The SES light came on a few days ago on my 03 cobra. I took it to autozone to have them scan for codes. 2 came up:

P0135-Upstream heated O2 sensor heater circuit fault- bank #1
P1131- Lack of upstream heated O2 sensor switch, sensor indicates lean- bank #1

I did have the midpipe removed recently to have a new clutch installed. My ? is which of the four O2 sensors is it? I’m guessing it’s the driver’s side, first one (closet to the headers) Any input would help. Thanks.

Travis

 

[FireRed04Vert]

That should be the upper sensor on the right (passenger) side of the car. I wonder if they didn't damage the wiring when they did the R & R. Sounds like the heater in the sensor isn't working. Check your wiring.