Well since the first of August we have been trying to get my dads truck 2006 f150 4x4 5.4 98,000 miles,back running. New plugs (changed with no problems) were great till about 5000 miles later when it just wouldnt go. In park you can rev it up, in gear no go. Finally after chasing our tail we took it to Ford. After 3 new injectors, 2 new coil paks, 1 MAF, they are down to changing out the cats. This is a California truck, and only Ford has the cats. msrp of 1000 for the lh assy and 1037 for the rh. This would change out all 4 cats. 2000 seems like way out there. Did some online checking through different ford dealers and so far have found some willing to give up to 100.00 per side discount. Anybody know of another place? What makes these 2006 California compliant cats worth so much?