The S62 motor in our Z8s uses 2 mass air flow sensors (MAFS) to measure air flow and mass in the intake tract and the engine's control computer uses this information to determine the appropriate amount of fuel to inject into the cylinders. If these MAFS become contaminated with pollen, dust, or soot, their readings will be adversely affected and the engine will tend to run too rich. They can also be contaminated with oil from reusable aftermarket air filters leading to rough running and a loss of power output from the engine. Up until now, the only practical solution was to replace the MAFS with new ones, a very expensive proposition. CRC has recently released a new product called Mass Air Flow Sensor Cleaner which makes cleaning MAFS a viable option. Just a quick spray of the sensor and the contamination is gone. Now, every time you change your air filter, no matter what type you're using, you can clean the MAFS at the same time and insure that your whole intake system is working properly. Check it out at www.crcindustries.com. CRC products are readily available at most auto supply stores. Grease Monkey