originally I thought it was the cat because everytime this happened a bad odor would arise. It does sound like this bad rattling and "chkerrrrrrrrrrrr" sound is coming from the engine now that i listen to it more. also my car starts to buckle and i think the rpms start bumping up and down at this point cause i know im not moving as fast as i shold be while im bucking a little. this happens when im flooring it and reaching high rpms.. WTF IS IT?!?! im scared to hear its my engine

 

ru getting a CEL....if so was it flashing.....when were ur coils/plugs changed last? What year and mileage of the car

 

could be a clogging cat.

 

If you thought it was a clogged cat, you should really have it checked out immediately. It would only take a few minutes on a lift for a shop to pop the cat off. Running high RPMs on a clogged exhaust is not the best for the engine.

 

What octane gas are you using?

 

+1 ......