Hey, I have an 1-4 motor in my van,  too.  It, too has a blocked off tube
protruding from the exhaust manifold..Sort of steel, thin walled with a bolt
hogged into the end of it blocking it off...
  Didn't see your pic, if you posted one since I get the digest and have a
dial up connection I rarely can follow up links from the list..
  I got 27.3 mpg on my last tank of gas, due to a lucky 300 miles of
tailwinds, or something..by the way..

  Don Hanson