So I have a 01 Monte Carlo LS 3.4L and went to go to work the other day and realized the car had no power. The car wont rev over 4000 rpms and wont accelerate over 60 mph. When you hold it at WOT if Just stays at 4000 rpm and the check engine light flashes. Code is p0302, cylinder 2 misfire.
Things I have done/checked:
-Tune up(plugs and wires)
-had ICM tested
-tested coil packs
-cleaned MAF and ran the car with it unplugged.
-Replaced upper and lower intake gaskets
-new PCV valve and replaced a couple of o rings that were causing small vac leaks since I took apart stuff that hadnt been messed for a while.
-checked compression 150 psi on each cylinder
-replaced injector o rings and injector 2, all injectors are firing because I can hear them clicking with a stethoscope.
-idle vac is about 16 in.
-fuel pressure is about 50 to 60 psi at idle and reved out.
-fuel pressure regulator is not leaking
After all this its still missing on cylinder 2 according to my scan tool but now I cannot get it to throw a code. At idle it runs fine, I am at a complete loss at this point. Car has 170k on it, please help.

Edit: I have also noticed my gas mileage has been getting worse and worse and was just about to do a tune up when this happened. Was getting about 22 mpg.

 

Sometimes the Catalytic Converter gets plugged and will do this. or maybe the exhaust system has a dent in it.
What about the Oxygen sensors up and downstream. I had to replace in my 3400 SUV.
And sometimes if the Trans Fluid is Brown it will have a struggle with power.
About all I can think of that has happened to me. Good luck.

 

Just an update in case someone ends up having the same problem I was having, it ended up being the ICM. Replaced it, drove the car a mile and all of a sudden it started acting fine. Not sure why it didn't fix it instantly but it is running fine now.

 

Thanks for providing the feedback of the actual issue. This may save someone else (maybe me) a few headaches.