There is no air filter in the thing. The engine is a 25 year old carburated dodge 360. I will check the PVC valve tonight, I need to put more oil in the thing to see if the lack of power is due to that, plus when I was putting it on the uhaul trailer it seemed to smoke a bit, needless to say the truck was to wide and long for the uhaul trailer anyway, and they didn't charge me for the rental. My friend got the boot out of his house that he rents, I was planning to take it there to work on it, I now have to look for another place to work on it for a couple weeks. I might take the weekend and just rent out a bay, couple hundred bucks. I'd rather find a garage or beside the garage where I won't be rushed and miss something.