My 1985 RX7 GS has a low-hanging line that appears to be a air line going to the catalytic converter, and when i got it the line hung down really low. While taking off from a stop and going around a corner it broke off. Is it a necessary piece? It only seems broken off at the catalytic because i wired it up with a metal clothes hanger to get home. But then again it was pouring rain when i fixed it and the car is rather low so i couldn't really see anything... Tomorrow I will take pics when i get it up on my ramps in the water free garage.

 

You'll need to repair the line and reconnect it to the catalytic converter. It brings air to the cat to help it complete oxidation and keep it cool. Without that air, the cat won't last long.

 

Do you have emission testing in Vt.? I live in NH and we do not have emission testing, just safety. I do not have any cats on my 85 GS. I run a header, presilencer and a high flow muffler. I just had the rats nest and air pump removed. You could take the air pump out and put block off plates where the air control valve is. I brought mine to a rotary expert down in Mass and they did it. I am sure there are write ups and diagrams for removing emissions if you search this site. You definately want to uncork that exhaust to get more power out of the engine.