Just after a new tank of gas the other day I received a check engine light and when scanned a PO304 code (mis fire on 4) and a PO327 code (driver side knock sensor). I have run out that tank of gas, used a fuel injector cleaner and filled up with 91 gas. Reset the code and the code comes back the same right away. New plugs and wires (from LR dealer) 1 year ago and 10k miles since then. Should I move forward with replacing the sensor? Engine does not appear to be running rough on inspection at idle, but does appear to be running underpowered.

Thanks for the input.

2004 Discovery SE7 - 68k miles, 12k on new dealer installed engine after sleeve slip failure (fortunately under dealer extended warranty)

Mike

 

Who's additive did you install?
Clear the codes and drive it hard, see what numbers come back.

 

Iz der an echo in here? Disco Mike and Disco Mike1....

 

LOL on the echo....

Cleared codes and drives normally around town. But when on freeway, going up a big grade at 65 mph engine light back on, same 2 codes PO304 and PO 327. cleared 2nd time and repeated under same condition, high speed, heavy climb.

Latest gas is chevron 91, full tank. Is this still knock sensor or something else?