First off...1991 Trooper, 2.8L.

Recently I have been replacing air filters as often as once a month. They appear to be getting clogged somehow and it is not from mud or dirt as it usually is. The outside of the filter is fairly clean while the inside of the element is somewhat black. Could this be caused by some sort of backfiring or exhaust getting sucked up into there? The only thing that I can see visibly wrong is the flex pipe from the exhaust manifold to the intake tube is loose. Is this for some kind of heater box for the intake? There is a small exhaust leak on each exhaust manifold near the gaskets. To me that would make sense why the air filter is black but it is only black on the inside. Also, when cold the truck does run a bit poor. I don't know if that is just nature of the beast or if something is wrong with the truck and if that is what is causing air filter clogs. Any and all help will be greatly appreciated.


Thank you,

Kevin