My truck seems to be running rich... I'm stumped trying to find out why. It's chugging gas, I get about 12mpg, and my exhaust tip has been on for less than 2 months and it's already coated wth black soot.

In the past 6 months it's had:

-New plugs
-New wires
-New fuel filter
-New air filter
-New 02 sensors
-New MAF sensor
-New distributor (entire assembly, not just cap)
-Seafoamed everything, through the brake booster line, through the intake, in the oil, in the gas
-Cleaned out the air box and throttle body

What am I missing?!

 

Did you seafoam after you changed the plugs? The seafoam could of fouled them