My check engine light is on. Ran the codes and can up with
P0134 O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 1)
P0135 O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1)
So what is the next step? new O2 sensor or am I looking for a short?

 

What year and how many miles on the truck? We need more information about the truck to really help. Have you traced the wires from the sensor back to where it plugs in at the engine? It could be the sensor is unplugged or it could be the sensor is really dead. Bank 1, Sensor 1 is driver side before the cat. The wires from it run to the back of engine kind of on top of the bell housing.

 

I am going to PM you.

 

Its a 2000 disco II with 90k.

 

By mileage, you are on the fence with this issue, usually I suggest 02's be changed at 100,000 miles, you defiantly have one down, the 135 doesn't bother me the 134 says replace.

 

I know this is very ignorant of me but does this look look like the Bank 1, Sensor 1, connection? I followed it up from before the cat. If so then it is connected and it looks like I am due for a new one. http://www.flickr.com/photos/38363192@N05/3531450984/

 

Kind of hard to tell, the red marker is blocking a lot of the picture, by the way why do you ask?

 

Make sure that you replace them in pairs.
So if you repalce one front O2 then you must also replace the other front O2.