Lean bank 1 and 2

[EMK]

My brother has a 99 Suburban 5.7L, 4x4.....Blah....blah....blah.

Anyway, he has a CEL that comes on and off after so many days. I hooked up my scanner and he had. codes for lean on bank 1 and on bank 2. As I was doing the live data I was watching the voltage on his o2 sensors and the voltage on b2 s1 was jumping from .830 to down to .140. That was the worst one, the others were real irradic but only jumping around maybe .150 or so back and forth.

Would the lean banks cause the o2 sensors to jump around?

And what would cause the lean bank codes?

 

[SunlitComet]

specific codes please.

 

[EMK]

I'll need to wait for it to come up again. I wrote them down and had it in my pocket, and well, it didn't fair well in the wash. I cleared it out when I had it hooked up.

 

[SunlitComet]

Let me know when you get them. Also update if something changes. BTW O2 sensors always jumps up and down it is how they do it or when they stop that what matters.