Bought an A4 with adblue delete so it seems, no codes or anything on dash however when scanned shows a code “lost communication to reductant control module”. 

had it scanned at a specialist to find the cause, the adblue was unplugged so they plugged it back in and it came up with engine light, multiple adblue codes. So unplugged it again and back to no errors except the lost communication code. They said looks like it’s been coded out as there’s no lights on dash when unplugged, is it normal to have the lost communication error code with the adblue delete & unplugged? 

also start/stop doesn’t work but I believe this is normal with an adblue delete? 

any information people can provide with this will be appreciated

Hello Tom,
When did you buy it, and was it bought from a dealer? 
Kind regards,

Gareth. 
 

1 minute ago, Magnet said:

Hello Tom,
When did you buy it, and was it bought from a dealer? 
Kind regards,

Gareth. 
 

About 6 weeks ago and no not a dealer mate 

If it's had an adblue delete it would suggest it's got a major problem with the adblue system and will need a lot spending on it if you want it working. If it were me I'd leave it alone. 

Given that Adblue is part of the car's emissions control system, I wonder if its deletion will affect the MOT test.

I do t think it does cliff as it'd just be a visual check.