Okay, I just noticed this today. I have an automatic, and when I switch to reverse, I hear a grinding sound, and I hear it again when I hit the gas when I reverse. I am pretty p****d about this, and I am going to the dealer sometime this week to get it checked. I was thinking about removing my OSCAI, but I doubt they are going to mess around or look around the airbox. DAMN!!!!!!!!!!!!!

 

If you want to be safe, you can take the OSCAI out. But, the tranny has nothing to do with the intake setup and they would have a really tough time proving that your reverse gear is messed up because of the intake. It seems like your reverse gear is messed up.