I installed the Westin wheel-to-wheel Platinum series step bars. The passenger side rear step has 1/4" LESS foot room then the drivers side.

I MADE SURE that I moved the bolt-hole adjustments as far out/away from the vehicle as possible. I measured it 3 times.

Is this due to the vehicle or could it be the Westin bars??

Overall, I like them, I used LOCTITE on the body mount bolts since they do NOT come with a lockwasher. I believe the factory uses BLUE LOCTITE on them (they were hard to take off and had blue all over the threads).

I also put LOCTITE on the 2 ALLEN HEAD bolts that sit beneath rear step. I didn't want them coming loose.

 

I installed Westin Platinum bars a couple of years ago and IIRC there was a bit of a difference between the sides. I didn't worry too much about it other than do the 'far out/away' as you did.

Since then, never really thought about it. The bars are not such that you see both at the same time and can see any differences, nor are the differences so great that you would see one side and think it is different than the other. I only use 1/2 the set, the wife uses the other 1/2 so there isn't really any comparison there either.

Both sides look and work great on their own.

 

This may sound stupid.. But I did this..

I actually mounted the Driver Side step on the passenger side and the passenger on the driver.. It looked just about as you described.

Maybe this could be your problem?