I have a 530D which is an E60 model. I have just had swirl flaps removed and blanked. As soon as the work was completed the car starting showing a 4501 exhaust gas re circulation deactivation fault, increased emissions. Initially the sensor on the manifold had been removed , so this was thought to be the problem. This has now been put back and the fault cleared, but the same fault keeps reappearing. I am at a bit of a loss as to what is causing the problem. Any advice great fully received.