Rpm Hanging

[tumbleweed]

I have a 2012 hayabusa has bcm filter dekelvic 9" cans and ecu flash by ivans preformance. The problem is that when I rev the engine the rpm falls as normal till 2000 rpm than slows way down to idle. start up cold is fine and the problem dose not happen while cold. I checked for vacuum leaks none found idle i stable warm no hunting performance is perfect no hesitation or flat spots and no popping on deceleration
I'm thinking maby a sync is needed or tis something in the program what say you?

 

[David Offor]

Might be worth looking into the tps (throttle position sensor), they can give similar issues to what you have described.
Lots of great mechanical advise on this site.
My main knowelge is on the gen 1s.

 

[tumbleweed]

I'' check that

 

[David Offor]

Water temperature sensor also, if it's ok, when cold, maf sensor also affects engine running.