I want to start a bit of a discussion here about WHY we should re-locate our IAT sensor.

The IAT sensor is supposed to measure the temperature of the air going into the engine, not going into the filter.. The way i see it is that if you were to re-locate the sensor to a different location, all you would be doing is tricking the computer to think its getting colder air when in actuality, the air will more than likely warm up before entering the intake manifold. Thus unnnecessarily richening the A/F mixture. The same result could be acchieved, by putting a Resisor inline or parallel with the IAT sensor in the stock location. ( i dont remember whichway would be appropriate here) Therefore i dont believe any benefit could be achieved by re-locating unless it make installation simpler with a CAI set-up.

Just like the resistor trick the PCM will learn if the A:F is too rich and trim it back.
The IAT is one of the sensors used to determain the ignition timing. Lower temp = more advance. You will need to keep an eye on KR. Like most other mods you need to plan things to work together.

So on my 03 SE will it be best to put it back in the pipe or in the filter do you loose or gain fuel milage. Im thinking I'll put it in the pipe.

One of the reasons is to keep the body of the IAT from heatsoaking from EXTERNAL air. The body of the sensor should be located far from the crossover pipe.

Your MAP sensor will also play a large role in timing advance and fueling, along with the IAT and O2 sensors, and the MAF sensor.

Series 1 cars and the 95 L36 do not use the MAP sensor input (as the only MAP sensors are for the SSEi'* boost gauge). Instead, these PCM'* have pre-programmed 'map tables'. This is why the resistor trick won't work on an OBD2 Series 2. The MAP sensor corrects for it, knowing the IAT value can't be right.