i did the rear disc recently.. and when i'm changing lane and stepping on the brakes at medium pressure.. i notice my rear is either locking up/ trying to spin out

i'm running dx front knuckles and rear disc with the stock prop valve.. would it cause that problem?

what's "wrong" with having the dx valve except not getting the disc's full potential? any safety issues?

 

I was running stock DX (VX/CX/LX) fronts with rear disks on my hatch with stock 3030 prop valve and I never had a problem of locking up.

 

Depends what year. If you have the 96-00 civic dx the prop valve is the same as the SI. The problem really lies in the fact that the rear are about the same size as the front. You need to upgrade to ex fronts to stop the rear locking up first.