erratic idle ...

[alves at email.unc.edu (Carlos Alves)]

Hey guys,

My 16v has an erratic idle, I noticed that my upper air intake boot is 
cracked, could this be the problem?? Where can I order a new one?? 
Instead of going stock, does anyone have an after market intake 
recommendations? I already have a K&N installed. 

Also, concerning my idling woes, I have noticed a vacuum leak on the 
vacuum thermoswitch. If you dont know what Im talking about, look here 
http://www.scirocco16v.com/tech_gallery/airsystem_scirocco16vdotcom.jpg
The whole switch on the side of the intake is gone, leaving me two 
wires, one going to the preheat valve (I dont think it is necessary, I 
actually removed this wire) and the other one going from the intake 
manifold. The wire from the intake manifold is unconnected and is the 
one that has a vacuum leak, but the weird thing is, my car has a more 
erratic idle when I plug that wire up and there is no leak. Just 
leaving it unconnected makes the care maintain a more or 
less "unerratic" idle, but still erratic nontheless.  Does anyone know 
what I am talking about?

I recently bought a Techtronics exhaust which bypasses the catalytic 
converter, but its the aluminum model.  Is installation on this easy or 
is welding required?

Thanks for all the help,

Carlos