Lean Bank 1&2 Z71 Tahoe

[Great Bambino]

Ok so I have a 02 z71 Tahoe and the service engine light keeps coming on and off every now and then. I scanned it and it says system to lean in both banks. I put on a K&n cold air intake and made sure everything was tight. My fuel pressure is at 45 and I know it should be higher. I was having a roughy idle but I replaced the idle air control valve and it runs smooth. But idk what's causing it to be lean in both banks! Any ideas??

 

[the04project]

I also have cai and had mass airflow sensor check engine light come on so I replaced that and the map sensor and it runs fine like yours but im getting the same reading as you. Talked to some people and got the responses of stopped up fuel filter, intake gasket and faulty injector. These are just ideas nothing for sure