Since I put on my 6637 filter. I have noticed that my exhaust smells like burnt oil. I gotta say I like the smell of burnt diesel, not oil.
Is this normal? I would rather put the old box back on than smell this oil.

 

mine doesn't.... how come you are smelling your exhaust? extended idleing? windows down?

 

check to see if you can see oil vapor coming up from somewhere. you may have poped off your ccv hose while putting the filter on. theres a box ontop of the driverside valve cover and a hose going from that box to the intake pipe check to make sure thats all intact still.