Hey, New member here! I've got a 99 V6 S/C Tacoma with 95k, deckplate, headers, URD kit, 2.2 pulley. It has been getting terrible gas mileage for a while now. The best it can muster is about 12 miles per gallon easy driving. I have done the following to fix this problem, to no avail: The 02 sensor has been replaced with an OEM unit, MAF cleaned & resistance tested, Throttle body thoroughly cleaned, new fuel filter, air filter, new plugs, tires properly inflated, all the vacuum lines are good. The truck runs fine, no obvious problems with the way it drives. Frustrated, I took it to the dealer, as soon they saw the URD kit they didn't want to touch it.

The AFR's don't seem to be off, at around 14.7 and the fuel trims seem normal too. I'm stumped, Maybe it it the TPS (No Lumbergh jokes lol) sensor?