92JDMSiR

i was driving around town today and I decided to get on the local interstate with a friend of mine. well what do you know, I encounter a fellow hybrider. I boosted up to 6 psi and took off. got to a toll and blasted through 1st and 2nd and tapped on third. after that I'm just driving and I let go of the gas and my car starts backfiring. not loud backfires but steady bom badaboomboom(lol). anthing under 4 grand I get the same thing. so I get home pop the hood and I noticed my fuel pressure went up like 3-5 psi. WTF!! what could have caused this. the only thing I did was install a boost controller yesterday and raised the boost from 3.5 to 6psi. when i boost up I'm in full rich. right now the pressure is at 38 psi with the vacuum on. how the hell is my fuel pressure rising by itself.
B16 drag 3 kit stock injectors, inline, 12:1 FMU