for your Mass Airflow Sensor (MAF), otherwise you'll have an even bigger problem to deal with. Also, check for cracks in tube that runs from the filter to the throttle body. I'm not sure what it's called -- breather box maybe? Anyway, if it's cracked and letting in air that can really mess with the computer and cause the engine to run badly. In a pinch you can clean it up and fix it with duct tape, but that's just a short-term workaround.

One other thing to consider - most auto parts stores have a diagnostic tool that can read the error codes in the computer. Even if the CEL isn't on, there may be information there that helpful - possibly a bad O2 sensor or clogged injector.

Good luck!