I was talking with a co-worker at another sattelite store of ours who, on the 1999 Powerstroke has never changed the oil/fuel filter/or air filter!!!!!I opened the air box up, and low and behold there was an inch of mud above the fins of the fram filter and leaves and tons of large bugs at the bottom of the air box!!the truck just turned 40,000 miles and has excessive blowby around the intercooler boots, but otherwise he says it runs fine... i couldn't believe it if i hadn't a seen it... this is a company truck BTW with a 17' flatbed and stakerails on it that hauls 3,000-12,000 pounds regularly. 
