I've read how to use resistors to desensitize the knock sensor in an OBDI car. The sensor can even be bypassed. However, does OBDII cars have any options (such as resistors) to desensitize the knock sensors? Other than the hit or miss options of using teflon tape or torqueing the sensor into the block lightely. Has anyone found those methods vaild? Thanks.

Michael

 

lt4 knock sensor ~$30

 

The LT4 knock sensor won't really help, it's the same thing/same part number as a regular OBDII knock sensor. If you were reffering to the knock module, then yes, it will work on an OBDII car just fine.

I wouldn't try unscrewing the knock sensor from the block and leaving it untight. You will risk it unscrewing completely and losing all coolant.

Do you have any specific reasons why you think you're getting knock?

 

Got me..... thats what I meant!

 

The only reason you would need to desensitize it is if you had proof of false knock. Real knock, you want to detect to protect your engine.
A scan tool would be how you could watch for knock and resulting timing retard.

 

I have the LT4 knock module. I've exchanged the stock and LT4 modules out with no change in the resulting knock count. I do have a scan tool to monitor the counts. Lower temperture thermostate, HPP programing, carbon cleaner, different gas: all have been used and rejected without a change in knock count. Recentely added headers with new o2 sensors. No change (increase or decrease) in knock count. Happens at the same time, same way, same amount on every scanned run. I've concluded I have false knock or the scan tool lies.

Does anyone know of a way to desensitize (not bypass) the knock sensor on an OBDII car? The use of teflon tape or tighetning the knock sensor into the block to spec (but no more) have been suggestions thrown out in the past. Have they worked for anyone?

Michael

 

Curious as to what rpm you see the knock. I was getting mine at around 4500, I think. The LT4 KM got rid of it.
What are you scanning with?

 

Rob,

I use the scan tool available through the HPP programer.

The recorded runs I've made are at WOT from a dead stop through to the end of second gear (1000' track). Knock counts start around 3500, increase to 4-5 counts by 4500, and fade to 1 or zero by the shift. Happens in first and second gear.

Cruising on the highway at 65 mph, around 1800 rpm. Any throttle tip-in will result in 1 or 2 knock counts. Aggresive throttle (not quite WOT) will result in 3-4 counts.

Been doing this for years. Always aggravating to try new things and never see results.

Michael