The rough idle started last night. The rough idle is strong enough to make the whole car shake. It will start at about 1200 to 1500rpms, pause at about 1000, and will then drop to about 750. The vibration gets worse when it drops as well. This will happen about 50-60% of the times the engine is at idle. It does this whether or not it is in neutral or in gear. I also have not noticed any loss in power.

I have a 2004 MT base model. With the RE-Amemiya intake box set, MS flywheel, and Tanabe TEAS.

 

Take it to a dealer. There have been problems with motor mounts that can result in the symptoms you mention. See the service bulletin at the link below. You may want to print it out and take it with you.

http://www.finishlineperformance.com...21-06-1559.pdf

 

Also the new flash from mazda will help out idle

 

engine is suppose to idle high when cold then drop down to around 850.

 

My 2004 also vibrates when it is in gear.. just at idle.. then is fine.. previos owner said dealer told him that it was in ned of motor mounts.. I have looked at the mounts and they look fine. but I have no idea what they looked like originally.

I am planning on taking the car to dealer in week or so to have oil changed and reflash. if it doesnt solve the issue then I am going to buy new mounts and replace them my self.. save about 300 in labor.. looks easy enough. I only see three or four bolts, and they can be reached through the wheel wells. mounts run 150.00 a piece.