I have a 2003 Passat TDI 130 sport & earlier in the year i had a ECU-re-map done but under hard driving there was a shed load's of black smoke visibale from the exhaust & also i think the MPG was down instead of up?

After a while i then decided to get the guy back & return the car back to standard ECU setting's.

The problem is that i am only returning about 28-30 MPG around town which i think is poor.

I was thinking of trying another ECU to see if there was any difference just incase the origional settings have not been restored?

There is no loss of power & the car drives fine at presant & just had a full service done a few weeks back with no problems found.