its under the y-pipe but above the turbos connected to the lim. it looks like some sort of accuator

 

I believe that you are describing one of the parts to the egr system.

 

Mazda's official name for it is "Control Value" Part number: N3A1-13-36Y

 

I took it off yesterday replacing the turbos and found a nice amount of carbon built up in the hole to the right, what could cause this and how should i go about cleaning it I scraped as much as i could out, but was woundering if i could use carb cleaner or somthing??
what problems whould my car have from such build up???

thanks for the reply

 

If it's the EGR valve, which is what I think you're describing, just leave it be or block it off. The EGR system is totally worthless on the FD, and Mazda even removed it entirely on the '95 cars.

Dale