Adam, at some point in time your coach had a diesel leak that hopefully has been fixed. Truthfully, it is one of the hardest smells to get rid of. I once ended up throwing away a pair of jeans and sneakers that got soaked in diesel. Jan wouldn't let me back in the coach until I took a shower and changed clothes. I smelled like diesel for several days. Even after washing the jeans three times the smell was there.
So, if you want to totally eliminate the odor, I'm afraid that you are going to have to rip out and replace at least some on the carpet material in your bays. I would start with the worst bay and go from there. Home Depot has a cheap grey indoor/outdoor carpet that is a suitable replacement. Save the old pieces for patterns, and I would wash down the floor of the bay with OdorBan or some such product.
I'm glad you didn't get drenched in diesel like I did. As bad or worse than a skunk. Say, the cure for skunk spray is baking soda and hydrogen peroxide. Might be worth a try on diesel smell.