So im the 2nd owner of my evo and the old owner got into a fender bender in the back right of the car. they did a really crappy job fixing it up.

i recently installed a jdm bumper and reused the old bumper retainer.

before with the usdm bumper there was a gap under the tail lights. bigger one on the right side and the same is going on with my JDM bumper.

So today I unbolted the 4 bolts in the back and the ones under the tail light. and when i pushed up on the bumper it closed the gap. is it possible the retainer is all warped up causing the gap?

 

hard to say without knowing the actual damage of the fender bender and how they repaired.
if the gap was there on the usdm, it is safe to say it would still be there on the jdm.
it could be warped. i dont know if its possible, but have u tried putting washers behind the beam to force it to angle upwards to close the gap? just an idea, dont know if it'll work as i never tried. but washers seem to be a fix it on some things. ie downpipe clearance from cross bars

 

yeah i used washers where the bolts go under the tail light it helped close the gap really well but the right side not all the way. the problem was the studs coming off the retainer were maxing out touching the top of the holes on the frame.

only reason i think it might be the retainer is because the bumper is mounted to it via rivets and follows its shape. there isn't anything really that's keeping it from moving up more to close the gap (other than the retainer it self). and this is with the bolts under the tails off and the 4 in the rear off. the only ones on are the 2 on each side which don't affect the gap because the qrt panel was not affected and the bumper lines up fine with it.