I've been trying to track down a false knock problem where I'm getting spark retard but no knock counts.
I've read on several posts that claim false knock could be due to headers.
How could this be if the headers aren't physically hitting on something?
Just because the exhaust is louder would not cause knock as thats a different frequency and the fact that the louder "noise" emitted is inside the manifold/exhaust pipe no matter if we had headers or not. We just don't hear it until the pipe is opened up more.
Just because we don't hear the exhaust as loud before the headers does not mean there more internal noise after installing the headers/cut out/ glass packs/straight thru muffs or whatever.

 

headers are louder and also more prone to making the rockers seem louder, so the knock sensor picks up this noise as false knock and pulls timing. Either get a tune with the knock sensor desensitzed or get an LT4 knock module to fix that. Trust me, thats just how it works...

 

stock manifolds dampen ALOT of the "knock" triggering noise from the exhaust(dense), headers can allow this to be transmitted to the sensor

 

True or false knock would show up in knock counts. How have you verified that your timing is being retarded?

 

I use DataMaster on my laptop for scan tool. Knock counts don't budge, gets 1-3 degrees of knock at idle and then goes away as rpms come up.

Sorry, I didn't mean to confuse the two, I don't think my knock is related to the headers in anyway, I just wondered across this as being a reason for false knock and didn't understand how it could be.
The headers have been on the car for months and this just started happening yesterday on my drive to work....ran this weekend without a lick of spark retard....but now I have another issue with a noise coming from the front of the motor which may be responsible for the knock, but since the knock counts aren't increasing, I think it may be something PCM related.

 

This has been argued for years... I dunno.. I'm running the LT1KM w/ Hooker LT's and Hi Tech 1.6nsa rr's and I've always had zero KR at WOT.

 

sorry...i think my KS was deleted with a tune. i deleted a bunch of stuff

any way...it's rumored that the thin wall design of the headers allows the noise to travel through them while the valves are open. not hard to believe since the thicker the metal the harder it is for noise to travel through...and i know for sure that my headers weighed at least 1/3 the weight of the manifolds. also...if you have steel valve covers instead of the plastic/carbon ones...noise will trave throught that too. i have a plastic valve cover on my jeep and it'a sooooo much quiteter than the aluminum stock unit.