AIR Tube fix?
 

93 F150 4.9l. where my airtube meets exhaust pipe rotted off. i connected peices together with heater hose and clamps, and it held for a month and then hose crumbled and its leaking again. doesnt seem like there is enough room to reweld it, although that could be my inexp. with welding talking. any ideas? and what exactly is the point of AIR anyway?

If you are talking about the long injection tube with the 6 fittings, you can get one from pciinc.com with fittings for about $120. It took me about 10 hours to change it, though I was taking my time and cleaning up things along the way. You will need to be careful with the fittings, they are thin and like to warp so that the line wrench doesn't fit anymore. If so, I used vice grips to loosen them. Lots of penetrant helps, too.

Don't forget the upper intake gasket. And it helped to take the valve cover off on mine, as well, so pick up a new valve cover gasket, too.

Good luck!