I have an 08 f150 with 156000 miles on it. Also have 35s on it.the throttle is very delayed in the lower gears. Has new plugs coils fuel filter. Been told it's the tps any thoughts. While accelerating I can feel it almost flatten out then picks usually doesnt start picking up till 2k rpm.any thoughts

 

It could be the computer retarding the timing due to low manifold vacuum caused by the high gearing/big tires. Install some 4.56 gears.