99 F-150, V-6

Bought this truck from dealer with 221K on it, have 2 other F-150's but with in-line 6's that have over 300K on them. This is my first experience with a V-6.
Truck ran fine on initial drive out, then began a slight miss @ idle.
Gas consumption escalated very much!! Put on computer. Shows bad EGR valve & a miss on 2 cylinders. Exp. Mechanic bud says there's a sensor on exhaust to check the EGR valve & most of the time the EGR is OK but the sensor leads have burned away.
Anybody have any knowledge? Could this be causing the miss & poor mileage?

The sensor your buddy means is the DPFE, the EGR pressure feedback sensor. It has two small rubber hoses running to a metal tube in the exhaust, and on these trucks those hoses harden, crack or burn through, and the sensor itself fails too. Both set EGR codes, and both are cheap to check, so that is a good first stop for the EGR code.

But a bad DPFE usually won't make two cylinders misfire. For the miss, check the plugs, plug wires and coil pack, then look for vacuum leaks around the intake, which are common on high mileage engines of this type. Fixing the miss should also help the mileage more than the EGR fix will.

Dana