engine putter's

[84LX89GT]

That is the air injection line from the air pump to the 3-way oxidizing catalytic converter (the one farthest down the exhaust pipe) There are the two lines coming from the catalytic converters, join together and go up and connect to the air pump. If this is disconnected you will have a fairly bad exhaust leak and it won't oxidize/react with the unburnt fuel being sent down the exhaust pipe. Having this disconnected will cause you to have a loud exhaust leak and possibly plug the catalytic converters because they won't be near as efficient at burning up the fuel because that type of catalytic converter requires a supply of air to catalyze a reaction with the fuel.

If you go to any Ford dealership or maybe an outlet parts store, you should be able to get you that line. It shouldn't be very expensive and it shouldn't be that hard to install either.

Good luck