My Scanmaster has been detecting some knock for the last while. (up to 10 degrees) It has been very inconsistent, and has occured with race fuel as well as regular 94 octane. The ignition is strong, the fuel lines have been flushed and the car runs very strong other than the odd time I get this timing retard. The engine internals are stock and I can't seem to find the problem but have deduced it is false knock.

I therefore have decided to use a 1 watt 3.9k resistor to bypass the knock sensor. However, I do not want to do this permanently so I was thinking of hooking up a switch to do it.

What i was thinking was to add a switch between the PCM and knock sensor. With the switch flipped in one direction, it would go through the resistor thus eliminating the knock sensor... however if I flick the switch to the other direction (in the event I use bad gas, etc.) it would bypass the resistor and go directly from the PCM to the knock sensor the way it was intended.

I was just wondering if anyone hear thinks this is a good idea or whether there are some issues I haven't looked at yet.

Thanks in advance for your assistance guys.

 

TTT for those who read in the morning rather than the evening.

 

I am also getting up to 10* knock retard... The idea sounds interesting to say the least.

I wonder if it would work.

 

I'll be trying to hook something up today. We'll see if I set any codes in the process. I'm bpassing the sensor only as a last resort, but I'm hoping if I hook up a switch I could always go back to the "stock"system.

 

I have noticed one thing on my car, and I don't know if it's like this all the time, but I only start getting knock retard once the car has gone into closed loop.. Well just over 3 minutes after startup anyway.

 

I do not beleive you can bypass it with a resistor but you can run a 2nd knock sensor mounted near in or arround the front bumper and run it so when you flip a switch it will go the "fake" knock sensor. It takes about 5secs for the computer the realize if the KS has been unpluged so by a simple flick of the switch all can be well.
This will be safe as long as you Knock is 100% false knock of you will be rebuilding a motor soon!!

After a Y pipe install on a freinds car he was getting 8+ degrees of knock from it banging arround durings shifts and did the above method for track use only or a freindly street race.