S.O.S. Help With Neon

Hey guys I have a problem i hope someone else has run in to with the neons and was able to fix the problem.
When you are starting out with the car the engine has power up till it hits a point where the engine seems to beholding its self back and gets very rough feeling as the rpm's grow it begins to fade, it acts the same for all gears, and i have noticed this before a few times but it is now constent. Any help on this would be fantastic.

The car is a 97 Neon 2.0L SOHC.
I don't know if it will mater but the battery was moved in to the trunk cold air intake and duel highflow exhaust was added.

Also once i put the HighFlow exhaust on i had to mod the O2 sensor becuase the car wanted to run very rich. (Car seemed to have this problem on and off before this mod).

Is your CEL on? When was the last time you had a tune-up?

Sorry What do you mean by "CEL"?
And i Keep up on my cars every weekend.
plugs cables and oil changed was done on 20th of april. (sounds stupid but i keep records of that).

Is your CEL on? When was the last time you had a tune-up?

LOL i just relized what you mean by cel. and no its not on.

After 5 days of looking over the car there is only one thing i can come up with on my own, I'm not 100% sure the ETR is even working.

Any of you guys have an idea on how to test this?

When you are driving this thing its like you're siting on a small jackhammer from 2000rpms up to 3000rmps then it levels out.

well what he means but cel ..... is the ceack engine ligt ...... is ur car a standard ..... it could be ur tps ..... cusing cluch chater at those rpms .....

how do your plugs/wires look? sort of sounds like misfiring.. i had the same problem in my camaro when one of the 8 plugs was disconnected :D i only felt the misfire when i stomped on the throttle.