Can my knock sensors be failing, and not give me a code for it? I get 7-13 mpg and a check engine flashing at random throttle positions including when I release the throttle. No stumbling, just no power. My code is a cyl #6 misfire.

03' disco 148k miles. New MAF, plugs, plug wires, o2 sensors, coils crank position sensor.

 

could a knock sensor be going and not throwing a code? anything is possible.

7mpg seems more like a bad O2 sensor than a knock sensor. A knock sensor is going to effect your timing.

I would go to whatever autoparts store you deal with and have them check for present code numbers, and then list them here.

 

That is one sensor, that when it starts to fail, it will usually throw a code.