Neighbour has just swapped an evo 5 for a V5 type-r today. He brought it here because its cutting out at idle.i took it for a spin and it drives ok through the revs but cuts out again at idle. i doubt the car is mapped and hes only got 95 unleaded in it(ive warned him) and its got a hks induction kit on it-would this be causing it? Also the speedo is not working-but car is showing no trouble codes. And he says the check light came on a few times-is that knock?