Is for clearing the EGR?
 

I just found this bolt on my old manifold that's out of the car and I was wondering? What's this for? I took it off and it goes right into the cast passage that brings the exhaust gas back to the intake. The exhaust gas ends up the BY THE THROTTLE BODY. There is a washer under the bolt head for sealing.

So I am thinking about flushing this passage with cleaner while holding open the EGR valve with a vaccuum pump. This should flush the EGR passage back into the exhaust.

Any thoughts on this?

The picture of the bolt location is in my locker :)

Can't hoit, but why bother? "if it ain't broke don't fix it"

Hi Beav :D Just the man I was thinking about when I posted this.

Do many cars have this feature? You know a port to access the EGR pipe that gets all clogged up?