I need to siphon the gas out of the car. I bought a siphon kit and put the correct hose from the pump into the tank, but the hose does not even get wet from the gas. The car was just filled up to capacity and should have close to 9-10 gallons in the tank. Must be some kind of anti-siphon block in the filler neck. Any hope of siphoning out the gas without removing the tank?

Siphoning gas out of a vehicle can be a hazardous and potentially dangerous task. Additionally, it may be ******* in some jurisdictions. If you need to remove gas from your 2002 Chevrolet Avalanche, it is recommended that you consult a professional mechanic or automotive technician for assistance.
If you still choose to proceed with siphoning the gas yourself, here are some general steps to follow:

1. Park the vehicle on level ground and turn off the engine. Be sure to engage the parking brake.
2. Locate the fuel tank. In the case of your 2002 Chevrolet Avalanche, the fuel tank is located underneath the truck bed.
3. Locate the fuel line. This is the hose that connects the fuel tank to the engine.
4. Insert a siphoning hose into the fuel tank through the fuel filler neck. Make sure the hose goes all the way to the bottom of the tank.
5. Use a manual pump or a vacuum pump to start the siphoning process. Be sure to follow the manufacturer's instructions for the pump you are using.
6. Once the fuel starts flowing, make sure to keep the siphoning hose lower than the fuel tank to maintain the flow of gas.
7. Continue siphoning until you have removed the desired amount of gas from the tank.
8. Once you are finished, remove the siphoning hose and dispose of the gas in accordance with local regulations.

Again, please exercise caution when attempting to siphon gas from your vehicle, and consider seeking professional assistance to avoid any accidents or legal issues.

A lot of thieves have tried, but I don't know of many that succeeded. I quit trying to siphon gas from the cap 30 years ago when they started putting springs into the filler hoses just to discourage the practice. And nowadays, anyway, the filler hoses have too many bends in them.

No, I don't think you can, but you could pull off the filler hose from the gas tank fitting and put in a siphon hose right into the tank there.
Another possibility is to shoot 12 volts battery power to the fuel pump (it could be done at the fuel pump relay's position), then disconnect the gas line at a convenient location, like at the fuel filter, and let the pump push all the gas out.

You can either siphon the liquid out of the tank or buy a hand pump and pump it out. You can get a hand pump at any automotive supply store (NAPA, Autozone) or Walmart automotive department. To siphon the liquid out get a length of hose and put it into the tank. Suck on the hose until the fluid is coming out of the hose and then lower the end of the hose to a level below the tank itself and let it drain into a container.

Be VERY careful with what you drain out. Even if it isn't all fuel it can still burn under the proper conditions. It is also not healthy for pets or children if they get into it. Dispose of the liquid properly. A service station may take it for you, or an auto supply store may be able to take it. If all else fails check with your local trash collection service to see if they will take it for recycling.

You can't. There is a roll over valve/ball in the neck of the tank preventing a siphon hose from entering the tank

if you cannot get a hose down the filler tube to use as a siphon(anti theft fitted) and there is no drain plug in the tank then a suggestion I can make is to remove the fuel hose from the outlet side of the pump and connect a long hose from there to your fuel tank and turn the fuel pump on. It may take a while but it will work

Almost impossible to siphon gas from todays' cars. Only way I know to do it, is to take off the filler hose from the tank. Then you could get a siphon hose into the tank.
An alternative is to pull the fuel line apart at the fuel filter, and use a jumper wire in place of the fuel pump relay. When done right, the pump will turn on and a stream of gas will come out the line at the filter. The pump relay is under the hood in the power distribution box. As you are unfamiliar with cars, you will need someone to jumper the correct terminals where the relay plugs into. If you get the wrong terminal, you could fry the engine computer. What needs to be jumped is the power feed for the fuel pump on one terminal to the terminal which has the wire going to the fuel pump in the tank. The relay has either 4 or 5 terminals depending on design. An experienced person can figure out the relay terminals to bridge or jump, based on the schematic that is on the side of the relay.

Because Toyota gas tanks are low,you may have trouble siphoning.Make sure hose and gas can are lower than gas tank.Use rubber hose,now suck on hose till you get gas in your mouth,and put hose quicly into gas can.Repeat if you have to.

Most vehicles have an anti-siphon on them to prevent that. You'll have to undo the clamp at the fuel fill up and sneak the siphon tube straight to the tank. You will also need to drop the gas tank and empty it thoroughly and even pressure wash it and let it dry thoroughly before reinstalling it. Hopefully no kerosene was drawn up into the sender unit or you'll have to bleed the lines as well. I suggest getting a siphon hose that has a ball in it that you can shake up and down to start the siphon so that you don't use your mouth (a dangerous practice).

unfortunately most fuel tanks are made so you can no longer siphon gas through the fill tube. if you want the fuel that badly you could disconnect the fuel line from the fuel filter and wait for it to drip out.

if it is less than half just drop the tank, otherwise stick a hose in the filler tube and siphon into a bucket. make sure that the outside end of hose is lower than the gas tank. if your worried about how to do it you shouldn't try it on your own. buy a siphon kit.