re: The tune-up thread

Pre filter as in the charcoal one? Naw, it doesn't do anything and doesn't cause any restrictions. Read on there somewhere where airflow was tested in the following scenarios: stock filter w/ charcoal filter installed; same with it removed; drop in K&N; drop in AFE; and no filtration at all (everything removed). Airflow was the same regardless and since the OEM filters flow more than the engine can use and filter better than K&N or AFE, thats what I go with.