They make a pipe for 09-10 models. They don't know, if it would fit the newer bikes. OEM exhaust for the respective models look damn near identical, based on the diagrams. Think it'll fit?

 

All I found on their website is a KLX250S slipon + midpipe.. From the looks of the midpipe nipple, it appears it will only work with the stock header. And, there is no O2 bung on the midpipe...

Perhaps a better choice is the FMF's (PC4 or Q4) for the newer EFI bikes..

 

The exhaust fits well. It does have an O2 bung. The muffler is quite long. I've been able to shave about 1/4" off the mid pipe. I would say the sound is a bit too much for my liking. Will try to get the "hard" db killer for it. It came with the mid db killer stock. ~3.5lbs lighter than stock.