this part came off my roomates 87 TII rx7.. same year/model car that I have but mine (as far as I know) never had this on it..

 

looks like aws....

 

AWS solenoid valve, aka air bypass solenoid valve.

Every FC in the US had one, but many get removed. Don't bother replacing it.

 

I agree, dont replace it. It causes the engine to rev to ~3000rpm upon cold start to warm up the cats/engine. I removed mine as soon as I knew what it was...Just block off the openings from it being removed with caps.

 

i thought it was the thermowax that causes the high rev and the aws assist by allowing more air to bypass.