Gert

For some time we have issues starting with motor management warning , error code indicated to camshaft sensor which has been replaced but the same problems returned. Other indications are misfirings on some cylinders. While driving the gas handle sticks now and then at RPM level of 2000-3000. Engine may also switch off sometimes. When engine is out of tune the airco is not working either. Does this sound familiar to someone? All suggestions appreciated.