so follow on i purchased an 01 sh, the previous owner said it has a race petrol cap one that doesn't need a key, something to do with pressure in the tank..

Anyone got any ideas what he meant or if i can change it to the one with a key.

 

You can return to a normal key cap if you wish. Tanks have vents in order to keep pressure stable, and the cap has nothing to do with that. It justs prevents the gas from coming out of the tank.

 

brilliant thanks ill return to key cap then!