Hi Simon

Sorry for taking time to get back on this one.

We found the split pipe behind the super charger and I expected that to be that! However, the fuel trims were still at +22. I tried resetting the ECU with two scan tools but nothing would bring them down.

The car went into a garage that specialises in Mercs and they just turned of the check light at the ECU saying ' the check light is over sensitive on these vehicles' [we dont have to have engine check lights here in New Zealand]

When the car came back we re checked the fuel trims and they were still at +22.

I am not happy with this 'fix' and have never heard of this issue with the check light. Maybe someone could enlighten me? We will be going back to the garage, I would just like some more amo.

Regards

Simon