Knock sensor?

[.Stevo.C.]

Plugged in my rs tuner yesterday and it flagged up 2 fault codes one of which was knock sensor faulty. Are there any symptoms with the car if the knock sensor is faulty? And what does this sensor do when it is working right?

 

[Darklite]

Have you serviced the car lately, you may have dislodged one of the wires on the knock sensor as it is next to the oil filter?

Try reaching under the fuel rail guard and giving the wires a push, i think it is a brown connector with a red and white wire. If you take the airbox out you may be able to see it (this is on a ph2 172). They are about £30 new.

 

[.Stevo.C.]

Yeah car was serviced not too long ago. It's a ph1 172 if that makes any difference.

 

[Darklite]

I had this and and air temp sensor fault, i gave the knock sensor connector a wiggle and the fault has cleared. I have ordered a sensor just in case it comes back. I'm not familiar with the ph1, but i'm sure it will be something similar. Hopefully someone with a ph1 can confirm that the sensors are in roughly the same place. RS tuner is worth its weight in gold when you have a warning light.

 

[.Stevo.C.]

Ok mate thanks for the help. Yeah it seems to be good for fault finding I wasnt expecting any faults to pop up as the car is running totally fine it's a bit heavy on fuel but I've got an idea what that might be.

 

[Darklite]

You probably need to change your pre cat lambda, as it may be overfuelling.

 

[.Stevo.C.]

Yeah that's what I had in mind need to change it soon I think it seems to be getting worse. Would this cause a flat spot too?

 

[Darklite]

Change it as soon as you can, if it is given false readings then it's possible that it could cause your flat spot. A specialist can confirm exactly what the lambda is telling the ecu to do. Fuelling problems are unlikely to do the cat any good.

Change it and see if you notice an improvement, with the age of these cars you can probably assume that most of the sensors will have seen better days.