Vw transporter limp mode 

Sometimes it won’t generate a fault code, sometimes the diagnostic gear is a bit shit. 😏 give it a clean, try a fuel additive and a good run first

@@bradauto thanks bud will definitely try giving it a good clean I’ve put some additive in the fuel the vans making this sound now almost like a dump valve when I’m in 3rd and 4th letting off boost any idea what that could be