bogging/stalling on acceleration

My brother has an 03 GA GT. The car recently started bogging down on acceleration. It tops out at about 25 mph, and full throttle causes the car to stall. He was throwing a code for the egr valve, and replaced that. Then he threw a code for maf sensor, swapped it and no change. We've also changed the MAP, TPS, IAC, O2, Coolant Temp sensor; so far, no luck. I don't know much about these cars, any suggestions?

also, fuel/ignition system all checked out

If from a dead stop, you LIGHTLY accelerate and vehicle slowly gets up to speed, but,

If from a dead stop, you lay into the accelerator and it doesn't go and doesn't even shift, chances are, you have a clogged exhaust(cat).....

Welcome to AF bradoboyer91 !

So what EXACTLY were the codes being shown ??

Sounds like someones wasted some money on guessing what the problem(s) are, not a good idea unless youre a millionaire. lol

And Tech II is right about the clogged Cat Converter causing similar issues. Next time youve got it running and its bogging with no power, look under the car and see if the converter is glowing red. IT should Not be red or glowing, if it is its prob bad.

Which this is a problem with the 02-03 models for some reason. Guess they used faulty materials in the catalist...not certain though..