1996 Tahoe, 5.7L 350 Vortec.
I'm getting O2 sensor P0131, and P0151 error codes when driving up mtn. passes. The error appears soon as I get close to 7000 ft. It happens from anywhere between 2500 rpm to 4000 rpm. On a consistent level. Soon as I clear it, it reappears.
I've replaced the O2...