hi this is my first post : problem with 2002 fabia 1.4 8 valve with central locking, sometimes tail gate will only open after a rear door has been opened and closed. have replaced lock but problem still persists, has anyone experienced this problem thanks in advance

How does your central locking work? On my car , you have to press the unlock button twice to unlock the tailgate (plus both rear doors and pass. front door) , If you only unlock the drivers door then the tailgate is still locked. Does it open with the internal release ok?

Me having big thumbs managed this a few times when I took delivery of my Superb, although soon realised there was a button on the remote for tailgate release. If it's a dodgy remote try using your spare for a while and see if it's that.