Mpg down a little

Evening all.

Im an old member returning and hope to use the forums as I used to once again.

due to a change in circumstance I’ve sold my A5 and bought another Mk1 VRS which I’m pretty happy with.

just done the G60 flywheel and VR6 clutch conversion and now I’ve started to use it the fuel economy doesn’t seem it’s best.

im trying to figure out if the car has been mapped or not, which I suspect it has.

that said, I feel an average 24mpg is certainly lower than my old one - im making an assumption that this is a likely llambda sensor fault.

what I’m trying to find out, is how I can check this using Vag Com / VCDS which I still have on my laptop from many moons ago - it’d be nice to see how its performing rather than just replace and hope!

apologies for such an essay. But thanks in advance!