Low Pressure Fuel Sensor is a must change when rough idle appears. $25 on eBay.
Dirty air filter, fouled spark plugs and bad gas can all contribute too.
These cars will try to compensate the air/fuel/spark when it's not quite right and at a certain point it can't compensate any more.
Typically an error code pops up and you can identify the exact problem but you will start to see the effects of a failing part before the code.
