Ok I'm hearing a million stories. Let me explain.

Last year I went to have my timing advanced at a dealership will doing maintenance. I was told they couldn't as my car is throwing a Rear O2 and Knock Sensor code which is affecting my timing. O2 I could careless as it means crap and I don't have to emission test until November.

I then go and run the seafoam which was great and it triggered the rear O2 again. Last week on my way to a meet the O2 CEL disappeared. Buddy used is OBD-II reader from his laptop and I threw no ghost knock codes what so ever.

So is my Knock Sensor gone? Or is the Rear O2 triggering this ghost code.

I've heard that when a Knock code shows up with another CEL and disappears once CEL is cleared then nothing is wrong. I've also heard that you can only pick up a Knock code even when CEL is not triggered by another code. I'm hearing a lot.

Can someone clarify? I have no CEL right now and no Knock code. but it comes up with my Rear O2 CEL. Is the knock gone or not?

Thanks,

 

bump....Anyone?

 

Knock sensor is fine.

 

Thanks, money can now go towards a WB O2 instaed

 

get a lil mini mallot and bang on the block by the knock sensor to test it

 

Explain in technical detail how this will simulate spark knock please.

 

knock sensor won't trigger a mil light. You can drive without even knowing it is faulty. It has nothing to do with 02. He cleared it and it may have just happened that the ECM never detected that it is faulty. -i am not sure if it is voltage triggered or resistance. So below a specific # then Mil light comes out.
You can drive with it bad but your ECM will retard the timing 7 degrees i believe and you might have reduced performance. That's all.
It's main purpose is to detect knocking and tell ECM there is a problem with fuel or motor and reduce timing not to cause any damage. If faulty ECM will go safe mode and retard it anyways.

 

That throws something in the mix. Well I didn't imply it was O2 related. More CEL related, that the code was being pulled when something else triggered a CEL and go away when nothing is throwing a CEL...I'm still probably gonna change it as the car feels sluggish in the low end.

 

KS = resistance. Test it after you DL the FSM and see where it should 'spec out' to.

On A32's, the KS code is often tripped by an O2 sensor.