Knock around 2800-3500 rpm Honda Civic FN2

[tmgt]

Honda Civic FN2 Type R (K20Z4) with Hondata FlashPro.

Current setup:

TSS intake
Custom sealed airbox with cold air feed from the fog light area
4-2-1 header
200 cell cat
2.5" exhaust
Shell V-Power only

I'm experiencing knock events in the low cam area around 2800-3500 rpm while driving uphill in 6th gear at approximately 750-850 mbar MAP. The issue is repeatable and mainly occurs under sustained load in higher gears.

What is confusing me:

* IAT is only around 25°C
* AFR tracks the target very closely (around 12.9 AFR in the affected area)
* Ignition timing is already significantly lower than stock in this region
* VTC advance has also been reduced compared to stock
* Knock retard is usually only 1-2°, but Knock Control increases significantly
* The knock counts are almost exclusively on cylinders 2 and 3
* I cannot reproduce the issue in 3rd gear under similar RPM and MAP conditions

I have attached the calibration and datalog. Based on the logs, does this look like genuine combustion knock, cylinder-to-cylinder fueling imbalance, VTC related, or possibly false knock/resonance from the exhaust/intake setup?

Any feedback would be appreciated.

[Spunkster]

Try reducing timing in that area and see if the knock goes away.

[tmgt]

Try reducing timing in that area and see if the knock goes away.

Thank you for the fast response. I‘ve already reduced the timing for 2-4 degree. The Knock doesent go away.

[CalibratEd]

Try reducing timing in that area and see if the knock goes away.

Thank you for the fast response. I‘ve already reduced the timing for 2-4 degree. The Knock doesent go away.

It maybe false knock. It’s possible you have something loose or a rattle.

-Ed