My truck has 136+K on the motor and when in WOT in 2nd gear the engine seems to "lay down" or run lean between 2500 and 3000 rpm. It only does this in second between the above mentioned rpms. Can someone point me in a direction to help me out? New injectors, a Superchip, fuel pump, what? I just changed the fuel filter this past weekend so I know thats not it.

Oh no codes are being thrown either.

 

Have you ever changed the O2 sensors? Usually only need to replace the two forward ones. Also, maybe your cats are going bad. Injector cleaner never hurts either. Finally, don't forget about cleaning the EGR.
What shape is your air filter in?

 

I just changed the O2 sensors Easter weekend, have a MAC CAI and the filter was just cleaned. Now the cats are a whole different story. Haven't smelt the dubious rotten eggs to let me know that they are bad, but they might be needed a replacement after 136K on them.

 

this is a case where you need a scan tool that can see pids for efficant diagnosios. could be a few sensors dpfe causes all sorts of weird problems seems like no 2 cause the same problem. maf could be getting dirty. fuel pump could be going. if you have a 4.2 V-6 it could be when the IMRC ports open the pcm cant keep up with the air charge for whatever reason. you could spend alot of money replacing stuff to try and figure this one out with out CEL on. there might be a memory code stored have you had autozone or anyone scan it at all?