Wondering Why this is happening?

[EclipseRolllin]

Ok first of all my first ? is this. Ill floor it and it goes to 15PSI and then drops to 10PSI and my 3rd gear doesnt seem to pull as hard. Plus when I floor it my Emergency Brake Light and Battery Light come on in the dash. Why is this happening. The mods if it might help are: Greddy Hardpipe Kit, Greddy Type S BOV, 3" Downpipe, 2.5" Custom Exhaust, No Cat, Air Intake. Plz any help is needed.

 

[Defiant]

Apparently you're running a T-25. It doesn't put out the volume to keep the engine boosted, the motor outruns the incoming pressure (to an extent).

Those lights coming on tend to indicate a failing alternator. I have no idea why the DSM wiring system does this. I wonder if you're shifting something in the engine room to cause a short- is the battery bolted down?