U.S models don't come with an o2 sensor. That's why the holes are plugged. To get rid of the popping you need to put in block off plates so that air isn't being injected into the exhaust.
I put a Hurricane bar from Webike Japan on mine. It has the bend of a European Touring bar. It simply replaces the stock bar. I tried to fit risers but it stretched wires, cables and brake lines. You'll just have to drill an 1/8'' hole in the right side of the bar for the switch gear/throttle...
I put a one up and one back on mine temporarily. I was unable to set the bars at the angle I wanted. They would hit the gas tank and interfere with my tankbag. I sent them back. You could probably get away with just a one up.
They said they could get one in 8 to 12 weeks when I ordered mine. A couple of days later they sent me an email saying they couldn't get one because it was on a nationwide backorder and I could cancel my order. That was on April 13th. I cancelled my order. I've been in contact with them the last...
I was using the 09 part number 5VX-21511-A0-P2 for the DEEP PURPLISH BLUE METALLIC fender. No luck with BikeBandit or RevZilla. I'm trying PARTZILLA now.