Wow, I just had one of those WTF moments and want to share.....On the other forum air filters were the topic, so I started to ck mine out and prices for my airfilter on line. Ive come to find out I've only had 1/2 of the filter I'm supposed to have! I should have another filter inside the one I use. Sort of a Pre filter ...that I haven't had in for THE LAST 5 YEARS !!! got 2 new filters ordered ... Oh well, the bus runs well so I just hope someone else can benefit from my rant.........s.........