Hey guys I am absolutely stumped on this code. I've started getting it a few months back, it's on the majority of the time but every now and again it'll go off for a day or so. I've got the following readings...

At idle:
Short term fuel trim: -2 to -12 fluctuating
Long term trim: -20.3
Intake Pressure: 10.8 inhg
MAF rate: 0.8 lb/min

At 2000 rpm:
Stft: -3 to +3
Ltft: drops from -20.3 to about -10.2
Intake pressure: 7.2 inHg
MAF rate: 1.3 lb/min

I got my stage 2 kit about 2 years ago and never had a problem until about a year ago. So I ruled out the tune. The kit of course came with new #42 injectors and new plugs. So I'm doubting it's a leaky injector but I mean I guess it's possible. I also just replaced my O2 sensors. Fuel pressure is normal. Any ideas? I'd greatly appreciate it.