I recently purchased the sound tube delete kit on AM, received it today and got it on. This has me thinking due to the cap being rubber, will it flex and deform over time(engine heat) with the cai suction and ultimately gets sucked in? if so what kind of damage is this going to do?

 

I'd have to see the cap to give a good guess, but I'd think it would have to be a pretty crappy cap for that to happen.

 

Its a rubber cap
http://www.americanmuscle.com/blowfi...te-1114gt.html

Started my car for the first time with sound tube delete. Normally cold start takes around 20 second for rpm to settle steadily and slightly under 900. But with the intake cap rpm kept bouncing up and down from 900-1k and caused exhaust to sputter. Double checked the tightening clamps it was on very tight any tighter it will rip through the rubber cap.

Decided to put my sound tube back on and rpm issue was gone.

 

That is weird. I assume the cap was leaking air which introduced unmetered air into the engine, confusing the computer. I'd try to find a thicker and tighter cap.