I have a fluid leek which is brownish in colour it is dripping behind the front offside innerwing are there any pipes located there

Just to make sure, when you say front left, do you mean the passenger side or driver side? Just asking because some people say front left and mean the passenger side because they are describing the position when they are facing the front of the car.

What does the fluid look like? Does it look like engine fluid or just water?

Normal a dripping injector makes a knocking noise when you first start up. To me it sounds like a leek. Try looking at the pipes any were above the exhaust or turbo. For the smell to come in to the car the leek will probably be at the front. I'm only guessing here. But I had the same thing on my range rover and it was a joint in the fule pipe spraying on to the block..Good luck

Transmission fluid is red, engine oil brownish. Drip some on a piece of paper towel to see the color

get car looked at by a mechanic ,sounds like its a brake pipe as these vehicle use a bundy type metal pipe for the hydraulics which includes the brakes and these pipes are prone to corrosion

Water is conensation from the air conditioning system. redish oil is most probably a antifreeze leak, does it look like a redish water? If so then its antifreeze toyota uses a pink/red long life anifreeze. most likley from a water pump which is right in that area

Depending on what colour the fluid inside the reservoir is:

Dark brownish viscous fluid is the power steering fluid.
Green or orange watery sweet smeling fluid is the coolant reservoir

it could be a bunch of thngs but i would guess its the lower intake manifold.

the pan under the motor is the oil pan. you can see the oil filter to the left of it (driverside). The plug is in the rear of it facing the back of the truck. On my 6.0l V8 the exuast pipe is rite behind it so when you loosen it have the drip pan ready to catch the oil as it will stream out fast at a wierd angle due to its location. The pan behind it is for the transmission.

I've had similar problems and had to have the water pump replaced.

your fuel sending unit could be bad or you have a leak in the gas tank.