popping on hard acceleration

my car has started popping back thru intake at full throttle as soon as u back off it runs fine.i have replaced the tps/ect/act/ put 24lb inj with calibrated c&l mas..yesterday after changing these pieces and the engine running about 45 min go down the road the car runs full throttle with no prob. now is doing the same thing again.I appreciate any help thanks

What year, engine, etc?

I think at WOT, the 24lb injectors are causing issues. At that point, the PCM uses preset fuel and spark tables and depends mostly on the TPS position, expecting you to have the original 19lb injectors. It will cause a rich condition which can be causing back fire.

I think at WOT, the 24lb injectors are causing issues. At that point, the PCM uses preset fuel and spark tables and depends mostly on the TPS position, expecting you to have the original 19lb injectors. It will cause a rich condition which can be causing back fire.
24lb injectors should not cause that problem.

What grade fuel are you running, what is your timing set at, what is your FP at with the vaccum line removed? To me it almost sounds like detonation. Please list all mods, IE heads cam etc.