It I’ll be fine regarding emissions, it’s post cat. It will be borderline antisocial though IMHO. I took mine off and refitted the original as I didn’t want to annoy the neighbours, and to be honest I didn’t think it matched the ethos of the car either really…
have av confirmed the fix? I’ve had the same issue, from looking at scantool data the reason behind the fault is the sensors reading below the threshold when cold (readings ok once warmed up) hence it won’t select reverse. The park off warning appears to be a side effect of the gearbox control...
You don’t need an sd3 for that. An autel ap200 (£60 next day from Amazon) will do everything you need short of any writes to vehicle. Failing that as safrane said, either listen with pdc engaged or wet your finger and rub across the sensors, you will feel any active. But cheap scan tool will...