91 Camaro rs no power on acceleration

Hum.I have a vehicle in my shop with the same problem but I checked the back pressure on the exaust. May be you have a converter problem it mite be stoped up gess you could try to remove both upstrem o2s and see if it makes a diff. Let me know what happens

You replaced a lot of parts, but were they actually faulty? Did you perform any of the tests that any manual would have provided you?
The one item that you did not mention is the EGR valve.

Too much or too little egr will cause the symptoms you described, without showing any fault codes.

For the cost of a new one replace this part and also replace the vacuum line for it. Typically the ends will expand over time causiing a vac leak.
Hand testings the egr is not always accuate. What feels good or ok can be very misleading.
Good luck, let us know what happens.
Kenvcr

Kenvcr, my egr valve is digital and each solenoid is working fine

Another guy posted to you about your exhaust, as the symtoms lead us that way.
Do what the importbasher suggested if you can. Remove the o2 sensor(s) and fire it up. You should feel a difference. How much exhaust is actually coming out the tail pipes?
If little or no change let me know. Do check to make sure the cat convertor is not plugged. These things rot from the inside out and cause a lot of headaches until it is figured out. Take a rubber hammer and bang on it to loosen and blockage. Not too hard as to punch a hole in it, but also listen for lots of debris rolling around inside it.
Off chance, when did you last replace the spark plug wires? Have you ever noticed a wettish looking spark plug when you last changed them? That is a sign that the plug is not firing properly and indicates that the wire may be faulty even though when tested with an ohm meter it's fine.
Let me know what happens.
Kenvcr

I did check the cat, I changed the plugs and the wires. I even changed the tps. Still have the same problem. I didn't however take out the 02 sensor thats my next move. But wouldn't the computer give me a fault code or a check engine light if the 02 were bad?

The purpose of removing the upstream o2s is not because we suppect them to be the fault but to free up any back pressure that mite be there due to converter failure once you remove them crank the engine to see if the power loss is any better