I have a 2008 GMC Yukon with the 5.3. I've been getting a p1175 code for a while and cant seem to fix it. I have an afm delete kit on it also if that changes anything. but I've been trying to get this fixed for so long and I'm tired of just part replacing. so far I've put new 8 new injectors in, upstream and downstream o2 sensors on bank 2, made sure all my exhaust leaks were fixed including repairing broken manifold studs, cleaning the MAF, Smoke testing for vacuum leaks with none found, and I also checked my whole intake manifold and gaskets for any way air could be getting in. My next step was coils/wires/and plugs but I'm looking for a way to make sure that what I'm doing is going to fix the problem. I've spent way too much money already and haven't been able to pass emissions because of this. Any tips on how to diagnose what is actually causing this?