Thanks for posting that. That device is a perfect case study in why one needs to be very careful.
This "chip" connects in place of the IAT sensor. I'll bet lunch at the restaurant of your choice that inside you'll find either a simple resistor, or an unpowered IC being used as a resistor. That is the only function it can possibly perform when substituted for the IAT.
You can save the $69 and perform the same function with a $0.10 resistor from Radio Shack.

Have a look inside an IAT-connected "performance chip" from a similar manufacturer (ProMax):

 

The above said, the PCM programming isn't the choke point in the 4.0's. The OEM unit is perfectly capable of additional performance provided you fix the real problem- inability of the engine to breathe. Exhaust, intake, throttle body, etc.

 

a real cold air intake (cowl intake or snorkel) helps massively with performance and mileage.

 

thanks that was great and even helps me

 

Speed and power have an inverse relationship to the thickness of your wallet.

 

 

It's somewhat physics oriented. I like it!

 

^^^this^^^
I Did the cowl snorkel (home brew), APN headers, 99+ intake manifold, bored TB, 703's, and a full tune up. about to go to a little bigger exhaust. You will definitely notice a difference with these and they are very inexpensive.