How does the AIR system work? The smog pump pumps air into the header tubes and the cat, right?

 

The AIR pump will pump air into the exhaust ports or the catalytic converter depending on whether or not it's running in closed loop. The ECM controls this with the divert valve. During open loop, the air is sent to the exhaust manifolds (port). During closed loop, the air is sent to the catalytic converter (divert). A couple other conditions effect where the air is directed (like deceleration).

The whole purpose is to reduce the emissions while the engine is cold, then assist the converter in breaking down the HCs.

 

ic. if I have the air tube to the cat disconnected will it hurt HP like if I had a header leak or what do you think?

 

No, it'll only effect emissions, and even then not as bad as not having a cat altogether. There are cats designed to work without the air port.

If your header leak is before the O² sensor though, that can effect HP since it'll read extra oxygen and richen your mixture.

 

the line to the o2 sensor was too short so we had to make an extention with copper wire. Does it made a differance? It looked like the stock line was steel.

 

It shouldn't, but with a 0-1 volt range to work inside, who knows? I think I've done the same on one of my cars and not had a problem so far. My repinned SD harness also goes from steel to copper on the knock sensor circuit (ESC "E" to "C" splice"). Not anticipating a huge problem...