One of my family members owns a Ford Econoline E150 modified with a roof extender and power wheelchair lift, however the engine is a stock V8 which runs on regular gas.
Anyway, after a fairly long road trip (300 miles total) the check engine light comes on and the car has a P0104 trouble code. Although googling tuns up pages saying it's the MAF or a leak in the intake, our MAF sensor is fine but there are signs of EGR trouble.
So my question is, what could be causing this EGR problem, and also, whether having a roof extender and power wheelchair lift would require we treat the car as a commercial vehicle/truck rather than consumer car since there's a bit more load on the car.
Also, the car is only at around 23,000 miles, however it is a 2002 Econoline, so I doubt this is due to the engine being worn down.