I GOT a JET Chip, What is it doing.

I have a 2000 Chevy C3500 with a 5.7 liter.

A buddy point out that there is a JET chip over riding something.

I looked over there and it looks like it is by passing one of the main hook ups.

Does anybody have any ideas what it is doing to my engine????

Thanks in advance.

It is advancing the timing, etc...basically altering some of the computers internal parameters for more power.