My 4x4 cossie does that. Recently put recon head on. She did a marvellous 0-60 on a private test track and generally drives ok, so I guess the timing is right, but once on the dual carriage way, pulling away from 50 there was kinda no power and this "baarrp baarrp" sound.

Any ideas what she's up to folks ?

 

BTT