Hi, My 93WRX seems to be pinking between 3-4000 revs. I use 97RON with Millers Plus C octane booster. Took into garage and they plugged it into computer but couldnt fault it in any way. Is it possible for the knock sensor to not work but show up healthy on diagnosis programme? Any other ideas, thanks ROB

 

Could be the ecu has been chipped in which case you would need to use 102 octane to be safe, only way to check that is to remove the kickplate and take the ecu cover off. Check for any afr devices that may be making it run lean. Do you have a boost guage ? If so what sort of boost is it pulling when it knocks. A faulty knock sensor will not cause pinking but it will not allow the ecu to retard when it happens. Faulty plugs/coil packs can also contribute.

Bob

 

Cheers Bob, Had chip removed soon after buying car so its running on original ECU. Decided to get it looked at again, booked in at DP Motorsports tomorrow, will post my findings( if any) Thanks ROB.