I have an 08 chevy avalanche ltz with a 5.3l with idle issues. For some reason everyttime I start the truck in the morning the idle is rough. The idle bounces up and down and sounds like it it's going to stall at times. I've replaced the oil pressure sensor and the manafold gaskets and I also put in a new throttle body. Only codes it's throwing is o2 sensor burning lean. Does anyone have any ideas