Hoping someone out there has some insight as into what may be going on with my mom's 2001 Cavalier Z24.

The rundown of the issues at hand are :

Idles at 1500 RPM's (No Less)
Upon Wide Open Throttle (Bogs Out/Misfires)

I have LITERALLY replaced everything I can possibly think of, that would be causing these problems with the car. My mom bought the car about 2 months ago, and everything was fine for the first 2 weeks (upon buying it, it did have the slightly higher idle, but would go back to normal after a few minutes of running) and then all hell broke lose within the motor of this car. I have read up on the Cavalier's (Especially the Z24's) and apparently the 2.4 Twin Cam is not the best of Engines.

It has 104,000 Miles on it

5 Speed Manual

The things I have replaced already :

Injectors
Fuel Rail
Fuel Pump
Spark Plugs
Ignition Coils
Ignition Control Module
Throttle Position Sensor
Idle Air Control Valve
MAP Sensor
Intake Manifold Gasket (Today)

And there's more I just cannot think of at the moment!!! This car is a huge headache to figure out. It drives fine if you are barely putting your foot into the pedal, but once you do, it starts to bog out and misfire. The only other thing I have in the back of my head, is that maybe, just maybe, the timing chain jumped slightly ...but I was told by a mechanic that if it jumped time, it wouldn't even start. I really just am hoping somebody out there may has some information or insight into what the hell is going on with this car, because as of this moment, I am at a loss not knowing what else to do with it.

My mom absolutely loves this car (why I don't know) and I would love nothing more than to get her back into it, but I cannot for the life of me, figure out this high idle and bogging out/misfiring situation.

Any help is greatly appreciated (and I apologize for the long post, just want all the details put out there)

Thanks in advance to anyone that can help me with headache.

(Also, there is no Catalytic Converter on it, so I know it's not that being clogged up)

 

It sounds likely that it did slip time. You'd have to verify it with a timing light to be certain. Are there engine noises as well?

 

Are there any engine lights on? Have you checked for codes with a scan tool? It can run if the chain jumped a tooth, Highly Unlikely...