Exhaust open flaps diy from under the hood easy version

This Mod should be a stickie!

 

Hi, I have bought a 2011 Cali, with the vacuum line mod already done.

My exhaust guy, who we met 25 years ago, is a well known producer now with “a lot” of expertise. Got in contact with him, regarding the fabspeed sports cat + xpipe sound that I like. He advised that the best way is to delete the cats only, and keeping the mid and rear as all original. (For him, changing only midpipe to a non resonated xpipe will have a very very low effect…)

I will try the non-cat downpipe + all oem solution and post a video.

I would like to know more about the oem setup for vacuum valve system. Without the cats, I may switch back to oem shut off system. I read that the original valve system stays on at the cold start, closes after warmed engine, opens at 3000sth rpm at comfort mode. What happens in sport mode? etc… Can someone share the logic?

best regards

 

Valves are open at start up. Close 1 or 2 seconds later. Valves open around 3000 rpm's in all 3 modes as I recall. (been a while since I've use esc-off)
The logic is to meet EPA noise limits for USA models.