Hey guys, '05 4x5 200,000k miles.......So i had my engine swapped with a reman about 5000 miles ago, added longtube jba's and cajun catless bpipes. Uprev tuned, but i'm still getting a p1283 code. I've replaced both upstream O2 sensors, fixed a vacuum leak caused by my bonehead mechanic using a big O ring and sealant instead of a gasket on the air intake, replaced a O ring he missed on a fuel injector (all other injectors check out) and my bank 2 AFR is still 13.5 when my bank 1 is 14.5. Shouldn't be the mass air flow sensor because bank 1 is fine right? Whatever my bank 1 AFR is, my bank 2 is off by 1. (for instance B1 at 15, then b2 is at 14, or B1 at 13, B2 is at 12). Not really sure what else to check for. Any help would be greatly appreciated!