Can a gas line be fixed if its rusted through enough to cause a leak

Well, you need a quick tutorial on your fuel system. Now to find a leak, stop trying to start the engine. You are only adding electrical charge to an already dangerous situation. Now stop and think this through. Modern fuel injection requires fuel under high pressure to operate. The injectors are immersed in this pressurized gas, as are the lines leading to them from the fuel tank's fuel supply line. So just by turning the key to ON, not start, you have initiated the process to start the engine, and that means the pump has operated for 2 seconds to put the fuel system under high pressure.

Now if you follow the fuel supply line (from the gas tank) to the engine connection, start here to find a leak. It is now under high pressure from here to the injectors on the engine- one for each cylinder-it should be dripping with gas somewhere. You could even turn the key to off after the pump has ran for 2 seconds. The fuel system is designed to hold pressure in the system for about 10 to 15 minutes, before slowly bleeding off. Enough time to search for a gas leak. A couple of other things associated with the system: there will be also a fuel return line from the injector rail, it goes back into the gas tank. both the supply line and the return line often run alongside each other. There is also a fuel pressure regulator, immersed in the fuel rail, a seal on that may have started leaking. If an air breather housing, or some cover prevents your seeing the fuel system entirely, then set it aside. You should be able to find the leak. Just be careful, have lots of rags handy, happy hands are learning hands.

rusted gas line

Ask for the 2 lines coming off the sending unit. to the main line. That should be enough for ordering them. be sure to change your feul filter while you're there good luck

i cracked my intake on a 2003 grand am i put alumaseal (aka) stop leak and worked great.

It can be. Anytime fuel is leaking, there is potential danger. I suspect the seal they're talking about is the one right at the top of the tank. Unfortunately you have to remove the gas tank to repair it. Quite likely this faulty seal will cause the engine light to come on also as it will cause a leak in the evaporative system.

if it is part of the sending unit,, u have to replace it,,any place else can be fixed cheap,,,

heres a couple of picture diagrams to help you, the most common area for a leak on these is the cooler line, this is the return line in which it is snaked in a s type shape to cool the power steering oil, these cooler line rots and leaks, so take a look at this first, its located at the bootm of the frame on the left side under the engine,hope this helps.

It seems that the backing plates are dirty and not allowing the brake shoe to return to it's proper position, rust builds up while not in use and causes the wheel to lock

Check to see if your filler pipe is rusted(The pipe where you put gas in). Do you smell gas stronger when you fill up your tank?

The OBD II code for P0400 is Exhaust Gas Recirculation Flow Malfunction.
I'm sure the only thing you have left is you may have to replace the EGR valve or check for any leak from the vaccum lines going to to EGR valve.