i was working on the car today and i found this,what does it control? i think its giving me a vacuum leak.

 

Thats the egr solenoid. I believe regulates the flow for egr. The green if your wondering is the power valve solenoid. Yes replace it.

 

What makes you think it's causing a vacuum leak? Have you tried bypassing it?

 

i have a off idle stumble that i cant figure out. only thing i can think of is a vacuum leak. i have replaced all injectors and gave it a full tune up. i have also replaced almost all vacuum lines and the others are still good. i saw this and thought it might be the problem. i haven't bypassed it but i did seal the crack and it made no difference.

 

James92SE had the same issue but had a replacement on hand. I believe the same one cracked on him.

 

I also had a my own irregular idle today, but figured it out before I quit for the day. My IACV was leaking